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2,337,500 |
Development and psychometric testing of the coping with breast cancer threat instrument.
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Women with a positive family history of breast cancer have a higher relative breast cancer risk. Research pertinent to this "at-risk" population has focused primarily on the early detection measures of breast self-exam, clinical breast exam, and mammography. Other specific primary prevention coping behaviors have received little research attention and, while there are instruments that measure general coping behaviors in the face of illness threat, there are no known instruments that measure coping behaviors specific to dealing with breast cancer threat. This study tested the psychometric properties of the Coping with Breast Cancer Threat instrument (CBCT). The CBCT was designed to measure primary prevention and early detection coping strategies used by women with family histories of breast cancer in response to their appraised breast cancer threat. The tool's format was modeled after the Jalowiec Coping Scale (JCS) and included use and effectiveness scales. Internal consistency reliabilities and content and construct validity of the CBCT were assessed in a sample of 209 women with a family history of breast cancer. Alpha coefficients for the CBCT's total use and effectiveness scales were .70 and .76, respectively. Principal components factor analysis with a varimax rotation revealed three conceptually relevant subcales that accounted for 52% of the variance in breast cancer threat coping behaviors. The CBCT was shown to be a reliable and valid measure of coping with breast cancer threat in a well-educated, European Amercian sample of middle-aged women.
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2,337,501 |
Prenatal exclusion of Crouzon syndrome by mutation analysis of FGFR2.
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Crouzon Syndrome is an autosomal dominant syndromic craniosynostosis characterized by premature closure of cranial sutures, exophthalmos, and midface hypoplasia. It is caused by multiple mutations in the fibroblast growth factor receptor 2 (FGFR2). We describe prenatal genetic testing of FGFR2 in a fetus of a mother whose previous child had Crouzon Syndrome due to an apparently de novo mutation, S351C. Sequence electropherograms of the exon 10 of FGFR2 encompassing the codon 351 revealed only the normal sequence, thus predicting a very high likelihood of an unaffected fetus. The study was confirmed by the birth of a normal neonate. We report the use of molecular genetic testing to exclude Crouzon Syndrome due to FGFR2 mutation prenatally. Prenatal diagnostic testing for a known mutation is a reasonable option for couples at risk for having a child with Crouzon Syndrome due to germline mosaicism. Molecular testing is more accurate and reliable than ultrasonography and provides families with reassurance.
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2,337,502 |
Hemoglobin E levels in double heterozygotes of hemoglobin E and SEA-type alpha-thalassemia.
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Coinheritance of alpha-thalassemia and hemoglobin E (Hb E) is prevalent in Thailand, where the gene frequencies of thalassemia and hemoglobinopathies are high. Hb E carriers with, concomitant inheritance of alpha-thalassemia 1 are known to have a lower level of Hb E. In this study, we reviewed the Hb E levels in Hb E carriers, who either had or did not have Southeast Asian (SEA)-type alpha-thalassemia, in order to seek a Hb E level that may be used as a predictor for concomitant alpha-thalassemia carrier status. The Hb E levels as measured by microcolumn chromatography in 844 Hb E carriers detected during a prenatal screening program for severe thalassemia at Chiang Mai University Hospital were reviewed. Hb E levels ranged from 12.3-35.0% (23.3 +/- 3.1%) in 751 Hb E carriers without SEA-type alpha-thalassemia and from 11.6-32.0% (17.0 +/- 3.7%) in 93 concomitant Hb E and SEA-type alpha-thalassemia carriers. The difference was significant (p < 0.01). However, the absence of SEA-type alpha-thalassemia could not be predicted by the higher Hb E level alone, as 3% of double heterozygotes demonstrated a level of more than 25%. Our study confirms a lower Hb E level in double heterozygotes with Hb E and SEA-type alpha-thalassemia. Nevertheless, the difference does not provide sufficient discriminatory power for the reliable exclusion of alpha-thalassemia status.
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2,337,503 |
[Wilson disease].
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Wilson disease is an autosomal recessive inherited disorder of human copper metabolism that leads to neurological symptoms and hepatic damage of variable degree. The affected gene ATP7B encodes a hepatic copper transport protein, which plays a key role in human copper metabolism. Clinical symptoms are complex with neurologic symptoms such as tremor, dysarthria, psychiatric disorders etc., predominant hepatic disease or mixed forms. Copper deposition in the liver results in acute liver failure, chronic hepatitis or liver cirrhosis. Early recognition by means of clinical, biochemical or genetic examination and early initiation of therapy with chelators or zinc-salts are essential for outcome and prognosis. Liver transplantation is an alternative in cases with acute and chronic liver failure and cures the hepatic disease. Frequent monitoring of drug therapy, adverse effects, and compliance is critical for the prognosis of the disease.
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2,337,504 |
Genotypic differences of MCAD deficiency in the Asian population: novel genotype and clinical symptoms preceding newborn screening notification.
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In contrast to its high prevalence in Caucasians, medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is reported to be an extremely rare metabolic disorder in the Asian population. The common MCAD gene (ACADM) mutation 985A>G (p.K329E), accounting for the majority of cases in Caucasians, has not been detected in this ethnic group, and the spectrum of ACADM mutations has remained unknown.</AbstractText>Biochemical genetic testing including plasma acylcarnitine and urine acylglycine analyses, as well as sequencing of ACADM was performed in a Korean family with a newborn who had an elevated octanoyl (C8) carnitine concentration by newborn screening (NBS). Genotyping of 50 Korean newborns with normal NBS results was performed.</AbstractText>We report the identification of the first Korean patient with MCAD deficiency, caused by a novel missense mutation in ACADM, 843A>T (R281S), and a 4-bp deletion, c.449_452delCTGA. The patient became symptomatic before notification of the abnormal NBS result. Both the father and a brother who were identified as carriers for the 4-bp deletion had mildly elevated plasma C8 and C10:1 carnitine concentrations, whereas the acylcarnitine profile was normal in the mother who carries the missense mutation.</AbstractText>The 4-bp deletion may represent a common Asian ACADM mutation, considering that it recently has also been found in two of the three Japanese patients in whom genotyping was performed. Greater availability of MCAD mutation analysis is likely to unravel the molecular basis of MCAD deficiency in the Asian population that might differ from Caucasians.</AbstractText>
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2,337,505 |
Risk calculations for cystic fibrosis in neonatal screening by immunoreactive trypsinogen and CFTR mutation tests.
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Although neonatal screening (or newborn screening) for cystic fibrosis (CF) is commonly practiced, systematic methods for accurate risk calculations are currently lacking.</AbstractText>We evaluated characteristics of the immunoreactive trypsinogen (IRT) test using the published data. The probability that a neonate has a positive IRT test, if the neonate is affected, a carrier, or a noncarrier, is approximately 1, 0.041, or 0.011, respectively. We provide methods to calculate genetic risks for a variety of commonly encountered scenarios in which neonates are positive by the IRT test.</AbstractText>Our Bayesian methods permit CF disease probabilities to be calculated accurately, taking into account all relevant information.</AbstractText>
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2,337,506 |
Concerns in a primary care population about genetic discrimination by insurers.
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Fear of genetic discrimination might deter participation in research or therapy. This is a major impetus for laws limiting insurers' use of genetic information, yet there is little information about the extent of this fear in the general population and how it varies by social factors.</AbstractText>This study measures concern about insurance problems relating to genetic testing, as part of primary-care screening for hereditary hemochromatosis (iron overload). Data come from a multiethnic, primary care-based survey of 86,859 adults in five field centers in the United States (AL, CA, DC, HI, OR), and one in Canada (Ontario). Logistic regression was used to model the probability of agreeing to the question "Genetic testing is not a good idea because you might have trouble getting or keeping your insurance."</AbstractText>Overall, 40.0% of participants agreed. Adjusting for other characteristics, African Americans and Asians were much less likely (OR = 0.52 and 0.39), and Hispanics were more likely (OR = 1.124), than Caucasians to express concern about insurance discrimination. Participants under 65 years old, US residents, and those without a high school diploma were substantially more likely to be concerned (ORs ranging from 1.4-1.6), as were participants with lower mental health scores. Education showed a nonlinear relationship, with significantly higher concern among both those with less than a high school education and those with a college degree, compared to high school graduates.</AbstractText>Concern about genetic discrimination varies substantially by race and other demographic factors and by nationality. One possible explanation for lower concern about Canadians and by people over 64 is that both groups are covered by social insurance for health care (Medicare). However, US residents in states with some legal protections against genetic discrimination had more, not less, concern than either Canadians or US residents in states with no legal protections.</AbstractText>
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2,337,507 |
Identification of novel RPGR ORF15 mutations in X-linked progressive cone-rod dystrophy (XLCORD) families.
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To test the incidence of mutations in RPGR ORF15 in six families with X-linked progressive retinal degeneration (cone-rod dystrophy [XLCORD], macular or cone dystrophy) and to undertake a detailed phenotypic assessment of families in whom ORF15 mutations were identified.</AbstractText>To amplify and sequence ORF15 in its entirety, a cloning strategy was developed. Families with mutations in ORF15 underwent electrophysiological testing, color vision assessment, color fundus photography, and fundus autofluorescence (AF) imaging.</AbstractText>Novel protein truncation mutations were identified in two families. In family A, a 2-bp mutation was identified in ORF15+A1094C G1095T, predicted to result in a truncated protein (E364D/E365X). In family B, a G-to-T transversion (ORF15+1176G>T) resulted in a nonsense mutation (G392X). Characteristics of phenotype in both families included progressive deterioration of central vision and subsequently night vision, mild photophobia, and moderate to high myopia. Ophthalmoscopic abnormalities were generally confined to the macula. A parafoveal ring of increased AF was observed, and electrophysiological evidence of a greater generalized abnormality in cone than rod responses were consistent with a cone-rod dystrophy phenotype.</AbstractText>The cloning strategy for ORF15 facilitated comprehensive sequence analysis in patients. Two families were identified with nonsense mutations, and clinical evaluation revealed them both to have a similar phenotype. The presence of a parafoveal ring of increased AF was an early indicator of affected status in these families. No disease-causing mutations in ORF15 were detected in four other families, suggesting that ORF15 mutations may not be the most common cause of XLCORD.</AbstractText>
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2,337,508 |
Polymorphism in the P-glycoprotein drug transporter MDR1 gene in colon cancer patients.
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The P-glycoprotein, a product of MDR1 (multiple drug resistance 1) gene, is a membrane efflux pump localized in epithelial cells in the small and large intestine, a part of the gastrointestinal barrier that protects cells against xenobiotics from our diet, bacterial toxins, drugs and other biologically active compounds, possibly carcinogens. In the present study, an association of MDR1 gene polymorphism and the occurrence of colon cancer were evaluated.</AbstractText>The study population consisted of 184 unrelated sporadic colon cancer patients and 188 healthy unrelated controls. Colon cancer patients were also subdivided into two subgroups, i.e., diagnosed before and after 50 years of age, and compared with age-stratified controls. The C3435T MDR1 gene polymorphism was identified using the polymerase chain reaction-restriction fragment length polymorphism method.</AbstractText>The distribution of wild-type and mutated genotypes was similar in the colon cancer patients and in the healthy controls. However, when patients diagnosed before 50 years of age were compared with the healthy population, carriers of MDR1 3435TT genotype or 3435T allele were at 2.7-fold (P<0.05) and 1.7-fold (P<0.05) higher risk of the disease development, respectively.</AbstractText>Genetic testing for C3435T MDR1 gene polymorphism may be a suitable test to evaluate the risk for colon cancer in patients under 50 years of age.</AbstractText>
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2,337,509 |
The diverse phenotype and genotype of pantothenate kinase-associated neurodegeneration.
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Pantothenate kinase-associated neurodegeneration (PKAN) is a rare autosomal-recessive disorder caused by mutations in the PANK2 gene. The authors report clinical and genetic findings of 16 patients with PKAN. The authors identified 12 mutations in the PANK2 gene, five of which were new. Only nine patients could be classified as classic or atypical PKAN, and intermediate phenotypes are described. Two patients presented with motor tics and obsessive-compulsive behavior suggestive of Tourette syndrome.
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2,337,510 |
Primary lateral sclerosis as a phenotypic manifestation of familial ALS.
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Primary lateral sclerosis (PLS) is a diagnosis of exclusion in patients with progressive spinobulbar spasticity and could be part of the clinical spectrum of ALS. Unlike ALS, which is familial in 5 to 10% of the cases, PLS has been described as a sporadic disorder in adults. The authors report two patients with PLS from unrelated SOD1-negative familial ALS families. These observations provide further evidence that PLS can be linked pathophysiologically to ALS.
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2,337,511 |
Two mutations in the HSN2 gene explain the high prevalence of HSAN2 in French Canadians.
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Hereditary sensory and autonomic neuropathy type 2 (HSAN2; MIM 201300) is a rare recessive neuropathy typically diagnosed in the first decade. The 1973 study of a French Canadian family led to the definition of HSAN2.</AbstractText>To demonstrate that the apparent higher prevalence of HSAN2 in Quebec is due to the presence of two HSN2 mutations and that carriers of different mutations appear to have a similar phenotype.</AbstractText>Through attending physicians, the authors recruited French Canadian patients with HSAN2. Exclusion of linkage to the known HSAN loci and linkage to the HSAN2 was performed using standard methods. Sequencing of the HSN2 gene was used to uncover the causal mutations.</AbstractText>A large cluster of HSAN2 patients comprising 16 affected individuals belonging to 13 families was identified. The mode of inheritance is clearly autosomal recessive. All patients originated from southern Quebec, and 75% are from the Lanaudière region. Whereas linkage to the HSAN1, 3, and 4 loci was excluded, linkage to the 12p13.33 HSAN2 locus was confirmed. Sequencing of the HSN2 gene uncovered two French Canadian mutations and a novel nonsense mutation in a patient of Lebanese origin, all predicted to lead to truncations of the HSN2 protein. The comparison of clinical variables between patients with different genotypes does not suggest any difference in phenotype.</AbstractText>Two founder mutations are responsible for the apparently higher prevalence of HSAN2 in French Canadians. Genotype-phenotype correlation does not suggest any significant clinical variability.</AbstractText>
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2,337,512 |
Association between family history of dementia and hallucinations in Parkinson disease.
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To identify familial risk factors for hallucinations in patients with Parkinson disease (PD).</AbstractText>Two hundred seventy-six outpatients with PD participated in the study. The presence of hallucinations was determined using a validated questionnaire, including items regarding the occurrence of visual, auditory, or other types of hallucinations. Family history of PD and dementia was determined by a structured interview and examination of medical records and affected family members. Patients with young-onset PD (<50 years) who reported another PD patient among their siblings were tested for parkin mutations. Stepwise logistic regression was applied for the detection of risk factors. The regression model included a set of family history-related variables (family history of PD and of dementia) and a set of disease-related variables (age, age at onset of PD, stage, duration of PD and of l-dopa therapy, l-dopa dose, and number of antiparkinsonian drugs).</AbstractText>Hallucinations were present in 32% of the 276 patients. Risk factors for hallucinations included Mini-Mental State Examination score (p < 0.0001) and positive family history of dementia (p = 0.0005).</AbstractText>Family history of dementia and lower Mini-Mental State Examination scores are risk factors for hallucinations in Parkinson disease.</AbstractText>
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2,337,513 |
The human solute carrier gene SLC35B4 encodes a bifunctional nucleotide sugar transporter with specificity for UDP-xylose and UDP-N-acetylglucosamine.
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The transport of nucleotide sugars from the cytoplasm into the Golgi apparatus is mediated by specialized type III proteins, the nucleotide sugar transporters (NSTs). Transport assays carried out in vitro with Golgi vesicles from mammalian cells showed specific uptake for a total of eight nucleotide sugars. When this study was started, NSTs with transport activities for all but two nucleotide sugars (UDP-Xyl and UDP-Glc) had been cloned. Aiming at identifying these elusive NSTs, bioinformatic methods were used to display putative NST sequences in the human genome. Ten open reading frames were identified, cloned, and heterologously expressed in yeast. Transport capabilities for UDP-Glc and UDP-Xyl were determined with Golgi vesicles isolated from transformed cells. Although a potential UDP-Glc transporter could not be identified due to the high endogenous transport background, the measurement of UDP-Xyl transport was possible on a zero background. Vesicles from yeast cells expressing the human gene SLC35B4 showed specific uptake of UDP-Xyl, and subsequent testing of other nucleotide sugars revealed a second activity for UDP-GlcNAc. Expression of the epitope-tagged SLC35B4 in mammalian cells demonstrated strict Golgi localization. Because decarboxylation of UDP-GlcA is known to produce UDP-Xyl directly in the endoplasmic reticulum and Golgi lumen, our data demonstrate that two ways exist to deliver UDP-Xyl to the Golgi apparatus.
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2,337,514 |
Hardy-Weinberg testing of a single homozygous genotype.
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No proper statistical test is available for the evaluation of deviation of a single homozygous genotype from Hardy-Weinberg equilibrium (HWE) proportion. We propose a 1-d.f. chi2-test. The power of the proposed test is favorable compared to existing HWE testing procedures. The applications of this test are discussed.
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2,337,515 |
Assessment of drug resistance mutations in plasma and peripheral blood mononuclear cells at different plasma viral loads in patients receiving HAART.
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HIV drug resistance mutations both in peripheral blood mononuclear cells (PBMCs) and plasma have the ability to influence the outcome of highly active antiretroviral therapy for HIV patients. PBMCs harbor archival proviral DNA, are a major source of HIV and also underdo latent infection during suppressive HAART.</AbstractText>The main objectives of this study were to assess whether specific viral load groups are better predictors of drug resistance and to examine the utility of PBMCs for drug resistance testing during HAART.</AbstractText>Patients were grouped into a plasma panel comprising of 100 patients and a PBMC/plasma panel of 45 patients. These two groups were further divided according to plasma viral load (low, medium and high). Therapy naive patients were also included. Resistance to protease and reverse transcriptase inhibitors was assessed in each group over different viral load categories.</AbstractText>Our data indicated that in addition to plasma, PBMCs also are a reliable predictor of drug resistance. Drug resistance mutations analyzed from each panel demonstrated that intermediate and high viral loads were strong indicators of drug resistance in both the plasma and PBMC compartments. Despite this, a significant portion of patients with high viral loads showed reduced levels of drug resistance indicating that factors including poor compliance, drug pharmacokinetics and host genetic factors are also likely to contribute to therapy failure. A significant degree of resistance to NRTI and PI resistance was found in treatment-naive individuals, demonstrating the transmission of circulating drug resistant HIV-1 variants.</AbstractText>Our data emphasize the need for stronger pharmacokinetic evaluation during HAART, especially for patients with intermediate or high plasma viremia. The utility of PBMCs as an alternative source of resistance profiling was also demonstrated, and this approach may benefit the assessment of future drug regimens for HIV-infected patients.</AbstractText>
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2,337,516 |
Polymorphisms in the TSHR (thyrotropin receptor) gene on chromosome 14q31 are not associated with mental retardation in the iodine-deficient areas of China.
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Mental retardation (MR) is one of the most frequent handicaps among children. Fetal iodine deficiency disorder (FIDD) is the commonest cause of preventable MR. However, not everyone in the iodine-deficient areas is affected and familial aggregation is common. This suggests that genetic factors may play an important role. Thyroid hormone (TH) plays an important role in fetal and early postnatal brain development. The thyroid-stimulating hormone (TSH, or thyrotropin) receptor (TSHR) is located on the surface of thyroid cells and binds TSH. It results in the production of thyroid hormones via the activation of adenylate cyclase and phospatidylinositol-dependent signaling pathways. Some researchers formulated the hypothesis that TSH receptor expression in the brain may be involved in local thyroid homeostasis through TSH stimulating the DIO2 activity. In the previous study, we have proposed that DIO2 may protect against FIDD in the iodine-deficient areas of China. The TSHR gene, which located on chromosome 14q31 is a potential candidate gene for susceptibility to FIDD. To investigate the potential genetic contribution of TSHR gene, we performed a case-control association study in Chinese Han population from the Qin-Ba mountain regions using four common SNPs in the gene (rs2284716, rs917986, rs2075173 and rs2075179). Pairwise linkage disequilibrium (LD) analysis showed that LD was observed between rs2284716 and rs917986 and between rs2075173 and rs2075179. Single-locus analysis found that all four SNPs in TSHR gene showed no association after correction for multiple testing. Haplotype analysis showed no significant differences in frequency for three sets of haplotypes based on the pariwise LD results. In conclusion, our association results suggest that TSHR gene is not a susceptibility gene for FIDD in the iodine-deficient areas of China.
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2,337,517 |
SMN1 dosage analysis in spinal muscular atrophy from India.
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Spinal muscular atrophy (SMA) represents the second most common fatal autosomal recessive disorder after cystic fibrosis. Due to the high carrier frequency, the burden of this genetic disorder is very heavy in developing countries like India. As there is no cure or effective treatment, genetic counseling becomes very important in disease management. SMN1 dosage analysis results can be utilized for identifying carriers before offering prenatal diagnosis in the context of genetic counseling.</AbstractText>In the present study we analyzed the carrier status of parents and sibs of proven SMA patients. In addition, SMN1 copy number was determined in suspected SMA patients and parents of children with a clinical diagnosis of SMA.</AbstractText>Twenty nine DNA samples were analyzed by quantitative PCR to determine the number of SMN1 gene copies present, and 17 of these were found to have one SMN1 gene copy. The parents of confirmed SMA patients were found to be obligate carriers of the disease. Dosage analysis was useful in ruling out clinical suspicion of SMA in four patients. In a family with history of a deceased floppy infant and two abortions, both parents were found to be carriers of SMA and prenatal diagnosis could be offered in future pregnancies.</AbstractText>SMN1 copy number analysis is an important parameter for identification of couples at risk for having a child affected with SMA and reduces unwarranted prenatal diagnosis for SMA. The dosage analysis is also useful for the counseling of clinically suspected SMA with a negative diagnostic SMA test.</AbstractText>
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2,337,518 |
Patterns of genetic variation do not correlate with geographical distance in the reef-building coral Pocillopora meandrina in the South Pacific.
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Dispersal may be a critical factor in the ability of reef-building corals to recover after major disturbances. We studied patterns of geographical structure using four microsatellite markers in seven South Pacific populations of Pocillopora meandrina, a major coral species from Polynesia. Variation within populations showed evidence of heterozygote deficiency. Genetic differentiation between populations was detected at a large scale (2000 km) between the Tonga and the Society Islands. Within the Society Islands, four of the five studied populations from Bora Bora, Moorea and Tahiti were not significantly different from each other. Unexpectedly, one of the three populations surveyed in Moorea was genetically different from the other two populations of this island (that were 5 and 10 km apart), and from the populations of the other two surveyed islands in this archipelago. We cannot rule out the possibility that this pattern is an equilibrium state, whereby short-range dispersal is locally more differentiating than long-range dispersal, as has been suggested by similar patterns reported in other studies. An alternative explanation that is globally consistent with all observations is that this is the signature of a large-scale destruction event, as for instance a bleaching event, followed by the recent restoration of populations by new colonists.
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2,337,519 |
Donor CD31 genotype and its association with acute graft-versus-host disease in HLA identical sibling stem cell transplantation.
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CD31 gene polymorphisms are implicated in the pathogenesis of graft-versus-host disease (GvHD) following haematopoietic stem cell transplantation (HST). We investigated the influence of CD31 genotype on the incidence of GvHD following HST from an human leukocyte antigen (HLA)-identical sibling donor. Donor and recipient CD31 codons 125, 563 and 670 DNA polymorphisms were determined in 85 cases of HLA identical sibling HST from two transplant centres. A correlation between CD31 genotype and acute GvHD was considered significant if observed in patients from both transplant centres independently. A strong correlation was identified between donor CD31 codon 125 genotype and the incidence of acute GvHD. Acute GvHD grades II-IV occurred in 27 of 46 (59%) recipients with a CD31 codon 125 leucine / valine heterozygous donor compared to nine of 39 (23%) recipients with a CD31 codon 125 homozygous donor (P=0.0019, relative-risk 2.45, 95% confidence interval 1.3-4.5). This correlation was significant in patients from both transplant centres (P=0.015 and P=0.019). We suggest that CD31 genotype may influence the function of donor-derived leukocytes and may be informative when there is a choice of comparable donors.
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2,337,520 |
Randomized comparison of group versus individual genetic education and counseling for familial breast and/or ovarian cancer.
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An efficient approach to education and counseling before BRCA1 and BRCA2 mutation testing is necessary for effective utilization of testing in the community. Education and counseling, when delivered individually, are limited by a shortage of trained health care providers as well as by financial and time constraints. The purpose of this study was to determine whether pretest education and counseling for breast cancer genetics in a group setting is equivalent to that provided on an individual basis.</AbstractText>One hundred forty-two patients at high risk for harboring a BRCA mutation were randomly assigned to group or individual education and counseling sessions. Group education was followed by brief individual counseling. Knowledge and Impact of Events Scales (IES) were administered at baseline and after education and counseling and at 1 week and 3, 6, and 12 months. Satisfaction with education and counseling was measured at completion of the session. Preferred method of education and counseling was solicited at 3 months.</AbstractText>There was no difference in knowledge or IES scores between groups. When stratified by genetic test results, knowledge scores showed no difference. Regardless of group, post-test IES scores in patients with positive results were higher than patients with negative or uninformative results but returned to baseline by 12 months. Participants were equally satisfied with either method they were assigned. Significantly more time was spent per patient in individual sessions (1.25 hours) than in group education (0.74 hours).</AbstractText>Our data suggest that group education and counseling may confer similar benefits compared with traditional individual sessions. Additional investigation of this approach in larger numbers of patients is warranted.</AbstractText>
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2,337,521 |
Alpha-1-antichymotrypsin gene polymorphism and susceptibility to multiple system atrophy (MSA).
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We investigated three genotypes (AA, AT, and TT) produced by signal peptide polymorphism of the alpha-1-antichymotrypsin (ACT) gene in 105 patients with multiple system atrophy (MSA) and age-matched controls. The frequency of ACT-AA genotype was significantly higher in patients with MSA (20.0%) than in controls (10.5%). The onset of MSA was significantly earlier and the disease progressed significantly faster in patients with ACT-AA genotype than in those with non-ACT-AA genotypes. The ACT concentration in cerebrospinal fluid was increased in patients with ACT-AA. To our knowledge, this is the first study to show that the ACT-AA genotype is a risk factor and modulating factor for MSA. Our findings suggest the involvement of ACT-relating inflammatory process in the pathogenesis of MSA.
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2,337,522 |
A 1.3 kb promoter fragment confers spatial and temporal expression of utrophin A mRNA in mouse skeletal muscle fibers.
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Upregulation of utrophin in muscle is currently being examined as a potential therapy for Duchenne muscular dystrophy patients. In this context, we generated transgenic mice harboring a 1.3 kb human utrophin A promoter fragment driving expression of the lacZ gene. Characterization of reporter expression during postnatal muscle development revealed that the levels and localization of beta-galactosidase parallel expression of utrophin A transcripts. Moreover, we noted that the utrophin A promoter is more active in slow soleus muscles. Additionally, expression of the reporter gene was regulated during muscle regeneration in a manner similar to utrophin A transcripts. Together, these results show that the utrophin A promoter-lacZ construct mirrors expression of utrophin A mRNAs indicating that this utrophin A promoter fragment confers temporal and spatial patterns of expression in skeletal muscle. This transgenic mouse will be valuable as an in vivo model for developing and testing molecules aimed at increasing utrophin A expression.
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2,337,523 |
[Clinical significance of HNPCC, surgical aspects of early recognition].
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A hereditary background may be demonstrated in approximately 15-20% of colorectal carcinomas. Familial adenomatous polyposis syndrome (FAP) constitutes about 1% of this patient population whereas hereditary non-polyposis colorectal carcinoma (HNPCC) makes up a further 3-6% of colorectal malignancies. The clinical features of HNPCC are dominant right colon localization, early age of onset, high prevalence of synchronous and metachronous tumors. Germline mutations of the so-called mismatch repair genes can be demonstrated in the genetic background of HNPCC. Screening and careful follow-up of these families are essential since the lifetime occurrence of colorectal carcinomas and HNPCC associated tumors has an 80-85% prevalence. The recognition of the affected families may be accomplished by taking a thorough family history, spanning several generations based on the Amsterdam and Bethesda Criteria, immunohistological investigations of the removed specimens and finally the exact identification of the pathologic MMR gene mutations. Radical surgical intervention is advised in cases of proven mutation carriers who are suffering from CRC. The index persons and their family members must be under regular control for their lifetime, with one-to-two year intervals to prevent fatal disease. The initiation of a national HNPCC register would further decrease the mortality and morbidity of the disease.
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2,337,524 |
Pragmatic approaches to genetic screening.
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Pragmatic approaches to genetic testing are discussed and appraised. Whilst there are various schools of pragmatism, the Deweyan approach seems to be the most appreciated in bioethics as it allows a historical approach indebted to Hegel. This in turn allows the pragmatist to specify and balance principles in various contexts. There are problems with where to draw a line between what is referred to here as the micro- and macro-level of doing bioethics, unless one is simply to be classified as a principlist. Whilst most discussions on genetics occur at a macro level, most specifying must be done also at a micro level - the clinical encounter. Whilst pragmatism encourages us to understand better social and scientific factors and puts into perspective statements like 'playing God', doubts are raised about the 'consensus' process and how one can put aside fundamental values such as the moral status of the embryo on which there is general disagreement. If those doing pragmatism do not endorse these values, there seems to be little ground for process and compromise with those who do. It seems therefore that pragmatism cannot ignore values, even those which are not endorsed by everyone.
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2,337,525 |
What should we want to know about our future? A Kantian view on predictive genetic testing.
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Recent advances in genomic research have led to the development of new diagnostic tools, including tests which make it possible to predict the future occurrence of monogenetic diseases (e.g. Chorea Huntington) or to determine increased susceptibilities to the future development of more complex diseases (e.g. breast cancer). The use of such tests raises a number of ethical, legal and social issues which are usually discussed in terms of rights. However, in the context of predictive genetic tests a key question arises which lies beyond the concept of rights, namely, What should we want to know about our future? In the following I shall discuss this question against the background of Kant's Doctrine of Virtue. It will be demonstrated that the system of duties of virtue that Kant elaborates in the second part of his Metaphysics of Morals offers a theoretical framework for addressing the question of a proper scope of future knowledge as provided by genetic tests. This approach can serve as a source of moral guidance complementary to a justice perspective. It does, however, not rest on the-rather problematic--claim to be able to define what the "good life" is.
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2,337,526 |
Clinical evaluation and emergency management of inborn errors of metabolism presenting in the newborn.
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Close to 500 biochemically diverse genetic metabolic disorders have been identified. Despite their diversity, these diseases share a number of features. First, the majority of patients with an inborn error present clinically with one of five general phenotypes; acute encephalopathy, progressive encephalopathy, primary muscle disease, primary liver disease or primary renal disease. Encephalopathy is by far the most common clinical manifestation of inborn errors of metabolism, and may be acute, intermittent, chronic (progressive), or even non-progressive. Although the five major phenotypes are a useful clinical guide, other clinical presentations of course occur, and some are virtually specific to a single disease or group of disorders. Second, almost all inborn errors are recessive in inheritance, and most of these conditions map to one of the 22 autosomes. Third, specific and effective treatment of inborn errors is often made possible by our understanding of their biochemical bases. Because inborn errors are genetic diseases, families with affected children can be made aware of the risk of recurrence, through genetic counselling. In many instances, presymptomatic treatment of affected relatives, carrier testing, and prenatal diagnosis can be offered. The types of inborn errors and their mode of presentation in the newborn are discussed, along with a schema permitting their rapid diagnosis. The principles of emergency and long term management are also discussed, with particular emphasis on those disorders that present in the newborn period with an acute encephalopathy, the so-called "small molecule" disorders.
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2,337,527 |
The utility of FT4 serum in newborns at risk for congenital hypothyroidism (CH).
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Thyrotropin (TSH) stimulates hormonogenesis using the iodate substrate and tyrosine amino acid. After various enzymatic reactions, thyroxine (T4) and triiodothyronine (T3) are released. Part of the hormone freely circulates in serum as free T3 (FT3) and free T4 (FT4). TSH is released after feedback. A study was undertaken to determine cut-off levels of FT4 to verify hypothalamic and pitutitary hypothyroidism. Both TSH and T4 were determined on blood spots by chemoluminescence and radioimmunology. TSH, T4 and FT4 were determined in control cases using an immuno-luminometric method. All newborns with TSH>3 mIU/l and FT4<0.6 ng/l were followed. Some of the positive cases may have resulted from iodine deficiency as a result of geography and environment. New risk values are being evaluated based on spot testing on the third day of blood sample collection. The ongoing study of new cut-off values in relation to birth day and the introduction of FT4 control serum level seems to prevent repeated measurements and promote quicker intervention by physicians thus preventing difficult genetic investigations.
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2,337,528 |
Newborn screening in Australia and New Zealand.
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Newborn screening began in Australia and New Zealand in the mid-1960's as local and pilot programs and implemented as country or state-wide programs around 1970. There are five programs covering all Australia and one for New Zealand. All screening programs are fully government funded, as is treatment for the conditions found by the screening programs and newborn screening is a universally adopted policy funded by the government. Some have additional involvement in program advisory committees. There are no major problems sustaining existing screening, however, some programs have financial problems with funding for new equipment. Other problems include storage and other uses of residual dried blood samples; consent issues; protocols for action after screening and introduction of expanded (tandem mass spectrometry) screening. New activities vary from program to program--working towards expanded newborn screening and collaborative projects for the evaluation of this screening and development of screening for lysosomal storage disorders. All programs are working towards automation of punching and testing and increased automated data handling and reporting.
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2,337,529 |
Storage and use of residual dried blood spots.
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Newborn screening policy for Australia and New Zealand is developed by a committee of the Human Genetics Society of Australasia and the Royal Australasian College of Physicians Division of Pediatrics. Each program policy varies according to the local laws and customs. The residual dried blood spot policy recommends that each screening program develop its own policy taking into account the ownership of the material and the time of retention. Cards and associated records should be stored securely with regard to privacy issues. All uses of residual materials and access to stored material should be documented. Programs should state what permission and documentation is required for the use of samples in 1) investigation of cases missed by the screening program, 2) screening program development, method development and establishing normal ranges for new and existing tests, 3) requests from families for the return of samples, 4) requests from health professionals to use residual material for other health-related purposes, 5) research studies, and 6) coronial and forensic purposes. Storage of the samples must be appropriate to intended future uses and appropriate quality assurance material stored with the samples. Relevant privacy, legal and ethical issues should be considered when formulating storage and use policies. Use of dried blood spot samples for purposes other than newborn screening should also be covered.
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2,337,530 |
The impact of first-trimester screening on AMA patients' uptake of invasive testing.
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Prenatal testing for AMA includes invasive procedures such as CVS and amniocentesis, which have risks. We sought to determine the effects of first-trimester screening (FTS) on referrals for genetic counseling and patients' decisions to pursue invasive testing after FTS was offered in 2002.</AbstractText>We compared AMA patients presenting for prenatal care who underwent early genetic counseling (<13 weeks' gestation) from 2001 to those from 2003. Charts were reviewed for maternal age, gestational age, past obstetric history, prior CVS or amniocentesis, abnormal ultrasound findings and decision to proceed with invasive testing. The two groups were compared using Student t-test and chi-square tests.</AbstractText>In 2001, 552 AMA women enrolled in prenatal care; 68 presented for early genetic counseling. In 2003, 728 AMA women enrolled in prenatal care; 172 presented for early genetic counseling. More counseled women chose genetic testing in 2003 than in 2001 (95% vs 79%, p<0.01). More patients elected an invasive procedure in 2001 compared to 2003 (71% vs 26%, p<0.01).</AbstractText>Availability of FTS results in more AMA women having early prenatal genetic counseling and choosing some form of genetic testing. Such women are less likely to choose invasive tests than those without access to FTS.</AbstractText>Copyright (c) 2005 John Wiley & Sons, Ltd.</CopyrightInformation>
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2,337,531 |
A major locus for hereditary prostate cancer in Finland: localization by linkage disequilibrium of a haplotype in the HPCX region.
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Prostate cancer (PRCA) is the most common cancer in males in the western world. In Finland PRCA has an age-adjusted incidence of 81.5 per 100,000. We previously reported that in Finland, the late-onset cases in families with "no-male-to-male" (NMM) transmission of PRCA accounted for most of the linkage to the HPCX region (Xq27-28). The aim of the present study was to test for linkage disequilibrium (LD) and haplotype-sharing around marker DXS1205 between cases from hereditary prostate cancer (HPC) families and population controls. The initial allelic association was performed between 108 PRCA cases and 257 population controls genotyped for 23 markers in the Xq26-28 region. This resulted in a highly significant nominal one-sided Fisher's exact P-value of 0.0003 for allele ''180'' of marker DXS1205. Subsequently, a similar level of significance was observed for the same allele for marker DXS1205 (P=0.0002) when comparing 60 NMM cases and 257 controls. These results were still significant after Bonferroni correction for multiple testing. Fine mapping efforts included the genotyping of four additional markers D3S2390, bG82i1.9, bG82i1.1, bG82i1.0 and four single nucleotide polymorphisms (SNPs) to augment the original markers around DXS1205.</AbstractText>Our major finding is that markers extending from ''D3S2390'' to ''bG82i1.0'' flank the critical locus, about 150 kb. Levin and Bertell's LD measure (delta), a guide to localization of a possible variant, was 0.42 and 0.41 for alleles of markers bG82i1.9 and DXS1205, respectively.</AbstractText>In this study, the most significant haplotype comprised the three tightly linked, contiguous markers: ''cen-bG82i1.9-SNP-Hap B-bG82i1.1-tel'' [''197-2-234''] among several possible haplotypes (nominal Fisher's one-sided P=0.003). The two transcription units mapping within this interval are the LDOC1 and SPANXC genes. Positional cloning of the HPCX gene(s) is being facilitated by this exploration of the Xq26-28 region. This study represents the first report identifying a haplotype in the Xq27-28 region for an association between HPCX and X-linked prostate cancer with no-male-to-male transmission in the Finnish population.</AbstractText>
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2,337,532 |
Fetal DNA detection in maternal plasma throughout gestation.
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The presence of fetal DNA in maternal plasma may represent a source of genetic material which can be obtained noninvasively. We wanted to assess whether fetal DNA is detectable in all pregnant women, to define the range and distribution of fetal DNA concentration at different gestational ages, to identify the optimal period to obtain a maternal blood sample yielding an adequate amount of fetal DNA for prenatal diagnosis, and to evaluate accuracy and predictive values of this approach. This information is crucial to develop safe and reliable non-invasive genetic testing in early pregnancy and monitoring of pregnancy complications in late gestation. Fetal DNA quantification in maternal plasma was carried out by real-time PCR on the SRY gene in male-bearing pregnancies to distinguish between maternal and fetal DNA. A cohort of 1,837 pregnant women was investigated. Fetal DNA could be detected from the sixth week and could be retrieved at any gestational week. No false-positive results were obtained in 163 women with previous embryo loss or previous male babies. Fetal DNA analysis performed blindly on a subset of 464 women displayed 99.4, 97.8 and 100% accuracy in fetal gender determination during the first, second, and third trimester of pregnancy, respectively. No SRY amplification was obtained in seven out of the 246 (2.8%) male-bearing pregnancies. Fetal DNA from maternal plasma seems to be an adequate and reliable source of genetic material for a noninvasive prenatal diagnostic approach.
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2,337,533 |
Mutation analysis of the SDHD gene in four kindreds with familial paraganglioma: description of one novel germline mutation.
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The familial paraganglioma syndrome is an autosomal dominant disorder characterized by the presence of carotid body paragangliomas and, less frequently, paragangliomas of the glomus jugulare, glomus vagale, and adrenal pheochromocytomas. Germline mutations of the genes for succinate dehydrogenase subunits D, B, or C (SDHD, SDHB, SDHC) have been identified in some kindreds with familial paraganglioma. In this study, we report the clinicopathologic features of four different kindreds with familial paraganglioma, which were screened for germline mutations in the SDHD gene. DNA was obtained from tumor and normal tissue, as well as from peripheral blood. Mutation analysis was performed by single-strand conformation polymorphism analysis and DNA sequencing. SDHD germline mutations were detected in the affected family members of the four families, as well as in several asymptomatic carriers. An identical mutation in exon 4 of SDHD (334-337delACTG) was identified in two apparently unrelated kindreds. The third family showed a germline mutation in exon 2 (W43X). The mutations present in these three families had been previously described in Spanish families, suggesting a founder effect. The fourth family exhibited a mutation in exon 2 of SDHD (170-171delTT), which had not been previously identified. The affected family members of the four kindreds showed paragangliomas, located in the head and neck region, and all of them were benign. These results confirm that genetic testing of SDHD may be a powerful tool for the identification of the syndrome in patients with multiple or bilateral paragangliomas.
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2,337,534 |
Specificity of SLC26A4 mutations in the pathogenesis of inner ear malformations.
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The traditional hypothesis concerning the pathogenesis of inner ear malformations holds that various types of malformations represent different stages of developmental arrest during embryogenesis. In order to verify this hypothesis, we surveyed mutations in the SLC26A4(PDS) gene, which were documented to cause enlarged vestibular aqueduct (EVA) and Mondini's dysplasia (incomplete partition of the cochlea), in 35 families with various types of inner ear malformations. In 25 families, the probands showed EVA or Mondini's dysplasia as the main temporal bone abnormalities, whereas the probands in the remaining 10 families revealed other types of malformations. In total, 7 mutated SLC26A4 alleles, including 6 missense mutations (A372V, A387V, T410M, S448L, T721M, and H723R) and 1 splice site mutation (IVS7-2A-->G), were detected. All mutated alleles segregated the malformations of EVA and Mondini's dysplasia, whereas no mutated alleles were found in the 10 probands with other types of malformations. SLC26A4 mutations were found in 22 of the 25 probands with EVA or Mondini's dysplasia, indicating that these might be specific to the development of Mondini's dysplasia and EVA. It is inferred that the pathogenetic mechanisms of the various malformations essentially differ, although their radiological findings appear to follow a continuum of morphological changes.
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2,337,535 |
Influence of maternal-fetal histocompatibility and MHC zygosity on maternal microchimerism.
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To investigate the relationship between maternal-fetal histocompatibility and maternal microchimerism, we developed a sensitive quantitative PCR assay for the neomycin resistance gene (neoR), and, in a mouse model system, used neoR as a noninherited maternal allele marker of maternal cells to detect and quantitate maternal microchimerism in tissues of neoR(-/-) N2 backcross progeny of (neoR(+/-))F(1) females mated with neoR(-/-) males. Using this approach, we obtained evidence for the presence of chimeric maternal cells in the brain, spleen, and thymus of all weanling and adult mice so tested. The numbers of chimeric maternal cells present in the spleen did not differ significantly from those in the thymus regardless of age or maternal-fetal histocompatibility. At all ages, brain tissue had higher level of maternal microchimerism than lymphoid tissue in mice MHC identical with their mothers, but the levels were similar in mice MHC disparate with their mothers. The levels of chimeric maternal cells in both brain and lymphoid tissue of mice with homozygous syngenicity and maternal allogenicity were similar, and tended to be higher than tissue-specific levels in mice with either combined maternal-fetal allogenicity or heterozygous syngenicity. Thus, MHC homozygous progeny had higher levels of maternal microchimerism than MHC heterozygous progeny. We conclude that normal mice possess small numbers of maternal cells in spleen, thymus, brain, and probably most other tissues, and that maternal-fetal histocompatibility influences the levels of these cells by mechanisms related to MHC zygosity of the progeny.
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2,337,536 |
The effect of synchronization on genetic parameters of reproductive traits in dairy cattle.
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Genetic evaluation and selection is one strategy for improving female reproductive performance. Many producers use synchronization of ovulation or estrus to manage reproduction. The objective of this study was to examine the effects of reproductive synchronization on genetic parameter estimates of days to first breeding (DFB), days open (DO), and pregnancy rate at 120 d postpartum (PR120). Data were collected from 64 producers participating in an artificial insemination progeny testing program and using Dairy Comp 305 herd management software to record reproductive treatments and events. Data included 18,359 records for DFB and 16,379 records for DO and PR120. Synchronization was classified by breeding codes at time of insemination. The traits DFB and DO were analyzed using a linear model with age at calving, herd-year-season, and parity as fixed effects and sire and residual as random effects. For PR120, a threshold sire model was used with fixed effects as in the DFB and DO models. Three models were applied to the complete data sets of all traits; a base model with no synchronization effect, an expanded model with a fixed synchronization effect, and an interaction model with a random sire by herd management interaction. Herd management categories were based on an individual herd's use of synchronization protocols. Also, data subsets were analyzed separately based on cow synchronization treatment and herd management categories. Synchronized records for DFB had on average 40% higher sire variance and 60% lower residual variance than nonsynchronized records. Heritability for DFB ranged from 0.01 to 0.09. Sire variance was 40% lower for DO and 25% lower for PR120 in first synchronized records than either later-synchronized or nonsynchronized records. Residual variances for DO varied by 3% among cow treatment categories and 14% for herd management categories. Heritabilities ranged from 0.03 to 0.07 for DO and 0.10 to 0.26 for PR120. Including a fixed effect for synchronization in the DO model reduced sire variance by 33% and residual variance by 10%. Sire by herd management interactions were less than 2% of the total variance for all traits. Accounting for synchronization, especially for DFB, may improve accuracy of genetic parameter estimates and animal evaluations.
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2,337,537 |
Hotelling's T2 multivariate profiling for detecting differential expression in microarrays.
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The most widely used statistical methods for finding differentially expressed genes (DEGs) are essentially univariate. In this study, we present a new T(2) statistic for analyzing microarray data. We implemented our method using a multiple forward search (MFS) algorithm that is designed for selecting a subset of feature vectors in high-dimensional microarray datasets. The proposed T2 statistic is a corollary to that originally developed for multivariate analyses and possesses two prominent statistical properties. First, our method takes into account multidimensional structure of microarray data. The utilization of the information hidden in gene interactions allows for finding genes whose differential expressions are not marginally detectable in univariate testing methods. Second, the statistic has a close relationship to discriminant analyses for classification of gene expression patterns. Our search algorithm sequentially maximizes gene expression difference/distance between two groups of genes. Including such a set of DEGs into initial feature variables may increase the power of classification rules. We validated our method by using a spike-in HGU95 dataset from Affymetrix. The utility of the new method was demonstrated by application to the analyses of gene expression patterns in human liver cancers and breast cancers. Extensive bioinformatics analyses and cross-validation of DEGs identified in the application datasets showed the significant advantages of our new algorithm.
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2,337,538 |
Testing hypotheses of speciation timing in Dicamptodon copei and Dicamptodon aterrimus (Caudata: Dicamptodontidae).
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Giant salamanders of the genus Dicamptodon are members of the mesic forest ecosystem that occurs in the Pacific Northwest of North America. We estimate the phylogeny of the genus to test several hypotheses concerning speciation and the origin of current species distributions. Specifically, we test competing a priori hypotheses of dispersal and vicariance to explain the disjunct inland distribution of the Idaho giant salamander (D. aterrimus) and to test the hypothesis of Pleistocene speciation of Cope's giant salamander (D. copei) using Bayesian hypothesis testing. We determined that available outgroups were too divergent to root the phylogeny effectively, and we calculated Bayesian posterior probabilities for each of the 15 possible root placements for this four-taxon group. This analysis placed the root on the branch leading to D. aterrimus, indicating that current distribution and speciation of D. aterrimus fit the ancient vicariance hypothesis and are attributable to the orogeny of the Cascade Mountains rather than recent inland dispersal. Furthermore, test results indicate that D. copei is distantly related to other coastal lineages and likely originated much earlier than the Pleistocene. These results suggest that speciation within the genus is attributable to ancient geologic events, while more recent Pleistocene glaciation has shaped genetic variation and distributions within the extant species.
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2,337,539 |
Quantitative trait loci for novelty/stress-induced locomotor activation in recombinant inbred (RI) and recombinant congenic (RC) strains of mice.
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The objective of the present study was to map and compare quantitative trait loci (QTLs) for an anxiety-related trait (novelty/stress-induced activation) in the AXB/BXA recombinant inbred (RI) and AcB/BcA recombinant congenic (RC) strains of mice derived from the A/J and C57BL/6J inbred progenitor strains. Activational responses to a novel open field (OF) were measured under identical stressful conditions (no prior handling or exposure to testing procedures) in both the RI and RC strains. Naive male and female mice were weighed, injected with IP saline and locomotor activity was monitored in a computerized OF apparatus for 15 min. Measures obtained from this experimental design included: (1) total activity scores, (2) time course of response (5 min time blocks over the 15 min session). Data for the RI strains were subjected to a QTL analysis using composite interval mapping. Significant loci were identified on chr 5 (D5Mit356, 41 cM), chr 8 (D8Mit305, 37 cM) and chr 14 (D14Mit36, 6 3cM). Single locus association analysis of the AcB/BcA RC strains identified 15 putative regions, 7 of which overlapped regions independently mapped in the RI strains on chr 1 (58.5-63.1cM), chr 4 (21.9-28.6 cM), chr 5 (19-45 & 74-86 cM), chr 6 (0.5-20.4cM), chr 9 (15-38 cM), chr 13 (47cM) and chr 19 (47cM). The loci identified on chr 5 near D5Mit356 (41cM) in both the AXB/BXA RIS and AcB/BcA RCS maps to a region containing the genes for several GABA(A) receptor subunits. Additionally, the present study provides further confirmation of a frequently identified QTL on chromosome 1. The results are discussed in the context of previous QTL studies of anxiety-related traits that have used genetic crosses that include the A or B6 progenitors.
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2,337,540 |
On the use of haplotype phylogeny to detect disease susceptibility loci.
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The cladistic approach proposed by Templeton has been presented as promising for the study of the genetic factors involved in common diseases. This approach allows the joint study of multiple markers within a gene by considering haplotypes and grouping them in nested clades. The idea is to search for clades with an excess of cases as compared to the whole sample and to identify the mutations defining these clades as potential candidate disease susceptibility sites. However, the performance of this approach for the study of the genetic factors involved in complex diseases has never been studied.</AbstractText>In this paper, we propose a new method to perform such a cladistic analysis and we estimate its power through simulations. We show that under models where the susceptibility to the disease is caused by a single genetic variant, the cladistic test is neither really more powerful to detect an association nor really more efficient to localize the susceptibility site than an individual SNP testing. However, when two interacting sites are responsible for the disease, the cladistic analysis greatly improves the probability to find the two susceptibility sites. The impact of the linkage disequilibrium and of the tree characteristics on the efficiency of the cladistic analysis are also discussed. An application on a real data set concerning the CARD15 gene and Crohn disease shows that the method can successfully identify the three variant sites that are involved in the disease susceptibility.</AbstractText>The use of phylogenies to group haplotypes is especially interesting to pinpoint the sites that are likely to be involved in disease susceptibility among the different markers identified within a gene.</AbstractText>
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2,337,541 |
The effects of normalization on the correlation structure of microarray data.
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Stochastic dependence between gene expression levels in microarray data is of critical importance for the methods of statistical inference that resort to pooling test-statistics across genes. It is frequently assumed that dependence between genes (or tests) is sufficiently weak to justify the proposed methods of testing for differentially expressed genes. A potential impact of between-gene correlations on the performance of such methods has yet to be explored.</AbstractText>The paper presents a systematic study of correlation between the t-statistics associated with different genes. We report the effects of four different normalization methods using a large set of microarray data on childhood leukemia in addition to several sets of simulated data. Our findings help decipher the correlation structure of microarray data before and after the application of normalization procedures.</AbstractText>A long-range correlation in microarray data manifests itself in thousands of genes that are heavily correlated with a given gene in terms of the associated t-statistics. By using normalization methods it is possible to significantly reduce correlation between the t-statistics computed for different genes. Normalization procedures affect both the true correlation, stemming from gene interactions, and the spurious correlation induced by random noise. When analyzing real world biological data sets, normalization procedures are unable to completely remove correlation between the test statistics. The long-range correlation structure also persists in normalized data.</AbstractText>
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2,337,542 |
Genetics content in the graduate audiology curriculum: a survey of academic programs.
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Astounding progress has been made in the identification and characterization of genes for hearing loss, which has led to an increasing role of genetics evaluation and testing in the diagnostic process for children with hearing loss. The importance of health professionals such as audiologists gaining core competencies in genetics has been recognized. The current report describes a survey of academic programs in audiology designed to determine the extent to which genetics content is included in the curriculum. Responses from 56% of existing academic programs indicate that 95% include some genetics content in their programs, with the total number of classroom hours ranging from 2 to 65. Most programs included information on basic genetic mechanisms, syndromes, and interpreting family history information, while many fewer reported covering the molecular basis of hearing loss, genetic testing, or ethical or legal issues. The results of this survey demonstrate the need to incorporate more genetics content into audiology curricula and suggest strategies for assisting audiology faculty with this process.
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2,337,543 |
Effects of periadolescent ethanol exposure on alcohol preference in two BALB substrains.
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Ethanol exposure during adolescence is a rite of passage in many societies, but only a subset of individuals exposed to ethanol becomes dependent on alcohol. To explore individual differences in response to ethanol exposure, we compared the effects of periadolescent ethanol exposure on alcohol drinking in an animal model. Male and female mice of two BALB substrains were exposed to ethanol in one of three forms--choice [water vs. 10% (volume/volume) ethanol], forced (10% ethanol in a single bottle), or gradual (single bottle exposure, starting with 0.5% ethanol and increasing at 2-day intervals to 10% ethanol)--from the 6th through the 12th week of age and administered two-bottle alcohol preference tests (10% ethanol vs. water) for 15 days immediately thereafter. All three forms of ethanol exposure increased alcohol preference in male and female BALB/cByJ mice, relative to findings for ethanol-naive control animals. Only gradual ethanol exposure produced an increase in alcohol preference in BALB/cJ mice. During extended alcohol preference testing (for a total of 39 days) of mice in the gradual ethanol exposure group, the higher alcohol preference of the gradual ethanol-exposed BALB/cByJ male mice persisted, but alcohol preference of control group female mice in this strain--formerly ethanol naive, but at this point having received 10% ethanol in the two-bottle paradigm for 15 days--rose to the level of alcohol preference of female mice in the gradual ethanol exposure group. This finding demonstrated that both adolescent and adult ethanol exposure stimulated alcohol preference in female mice of this strain. Across days of testing in adulthood, alcohol preference of the gradual ethanol-exposed BALB/cJ mice decreased, resulting in a lack of effect of gradual exposure to ethanol on alcohol preference in both male and female mice of this strain during the period of extended testing. These strain differences support a genetic basis for the effects of ethanol exposure on alcohol preference and fit within a body of literature, showing substantial individual differences in the effects of ethanol exposure among genetically undefined rats and differences in response to ethanol exposure among inbred rat strains. Exploration of the mechanisms underlying this gene by environment interaction in a mouse model may help elucidate individual differences in the effects of ethanol exposure in human beings and contribute to the understanding of the causes of alcoholism.
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2,337,544 |
Normal acylcarnitine levels during confirmation of abnormal newborn screening in long-chain fatty acid oxidation defects.
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We report two infants identified by tandem mass spectrometry (MS/MS) of neonatal blood spot acylcarnitines and confirmed by molecular genetic analysis to have long-chain fatty acid oxidation defects. In both cases, acylcarnitine concentrations in confirmatory plasma samples were normal. None the less, molecular testing identified trifunctional protein (TFP) deficiency (McKusick 600890) and very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (McKusick 201475).
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2,337,545 |
Protein toxins: intracellular trafficking for targeted therapy.
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The immunotoxin approach is based on the use of tumor-targeting ligands or antibodies that are linked to the catalytic (toxic) moieties of bacterial or plant protein toxins. In this review, we first discuss the current state of clinical development of immunotoxin approaches describing the results obtained with the two toxins most frequently used: diphtheria and Pseudomonas toxin-derived proteins. In the second part of the review, a novel concept will be presented in which the roles are inverted: nontoxic receptor-binding toxin moieties are used for the targeting of therapeutic and diagnostic compounds to cancer or immune cells. The cell biological basis of these novel types of toxin-based therapeutics will be discussed, and we will summarize ongoing preclinical and clinical testing.
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2,337,546 |
Identification of a turnover element in region 2.1 of Escherichia coli sigma32 by a bacterial one-hybrid approach.
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Induction of the heat shock response in Escherichia coli requires the alternative sigma factor sigma32 (RpoH). The cellular concentration of sigma32 is controlled by proteolysis involving FtsH, other proteases, and the DnaKJ chaperone system. To identify individual sigma32 residues critical for degradation, we used a recently developed bacterial one-hybrid system and screened for stabilized versions of sigma32. The five single point mutations that rendered the sigma factor more stable mapped to positions L47, A50, and I54 in region 2.1. Strains expressing the stabilized sigma32 variants exhibited elevated transcriptional activity, as determined by a groE-lacZ fusion. Structure calculations predicted that the three mutated residues line up on the same face of an alpha-helix in region 2.1, suggesting that they are positioned to interact with proteins of the degradation machinery.
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2,337,547 |
Genomewide screen for pulmonary function in 200 families ascertained for asthma.
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Changes in pulmonary function are important in determining asthma outcome. Genetic factors may influence airway obstruction in asthma. We performed a genomewide screen in 200 families of probands objectively diagnosed with asthma in the 1960s to identify chromosomal regions related to changes in pre- and postbronchodilator lung function (FEV1, VC, and FEV1%VC) and assess influences of early-life smoke exposure. Smoking (pack-years), age, sex, and height were covariates in variance component analyses. Significant evidence for linkage of pre- and postbronchodilator FEV1%VC was obtained for chromosome 2q32 (LOD,4.9, increasing to 6.03 with additional fine-mapping markers, and 3.2, respectively). Linkage existed for chromosome 5q for pre- and postbronchodilator VC (likelihood of disease [LOD], 1.8 and 2.6, respectively). Results for pre- and postbronchodilator FEV1 were less significant (LOD, 1.5 and 1.6, chromosomes 11p and 10q, respectively). Results were not affected by passive smoke exposure. There is significant evidence for linkage of FEV1%VC to chromosome 2q32 in families of probands with asthma, 35 cM proximal from linkage previously observed in families of probands with early-onset chronic obstructive pulmonary disease. Thus, there may be multiple genes on chromosome 2q that are important in determining presence and degree of airflow limitation in families ascertained for obstructive airway disease.
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2,337,548 |
Batch-to-batch consistency of human-derived gonadotrophin preparations compared with recombinant preparations.
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Different gonadotrophin preparations derived from human urine or manufactured by recombinant technology are currently used in clinical practice for the treatment of infertility. It has been widely assumed that gonadotrophin products manufactured by recombinant technology have better batch-to-batch consistency compared with human-derived preparations and that this potentially will be shown to provide a more constant clinical response, but there is little evidence for either statement. This study compared the batch-to-batch consistency between urinary-derived and recombinant manufactured gonadotrophin preparations using standard analytical techniques, as well as a novel in-vitro follicle bioassay to evaluate the consistency of the biological response at the target organ. Oligosaccharide isoform profiling, immunoassay testing, size exclusion chromatography analysis and in-vitro bioassay testing of urinary derived gonadotrophin preparations (MENOPUR and BRAVELLE) confirm that these products display a high degree of batch-to-batch consistency, similar to recombinant FSH (GONAL-f) either filled by mass or bioassay. The data also suggest that the batch-to-batch variation is independent of the manufacturing procedure (filled-by-bioassay or filled-by-mass) for the recombinant preparation (Gonal-f), but that the total FSH bioactivity delivered from a single dose preparation after reconstitution differs between the two manufacturing procedures.
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2,337,549 |
Breast cancer risk in BRCA1 and BRCA2 mutation carriers and polyglutamine repeat length in the AIB1 gene.
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Marked variation in phenotypic expression among BRCA1 and BRCA2 mutation carriers may be partly explained by modifier genes that influence mutation penetrance. Variation in CAG/CAA repeat lengths coding for stretches of glutamines in the C-terminus of the AIB1 protein (amplified in breast cancer 1, a steroid receptor coactivator) has been proposed to modify the breast cancer risk in women carrying germline BRCA1 mutations. We genotyped the AIB1 repeat length polymorphism from the genomic DNA of a group of 851 BRCA1 and 324 BRCA2 female germline mutation carriers to estimate an association with breast cancer risk modification. Hazard ratios (HR) were calculated using a Cox proportional hazards model. For BRCA1 and BRCA2 mutation carriers, analyzed separately and together, we found that women who carried alleles with 28 or more polyglutamine repeats had no increased risk of breast cancer compared to those who carried alleles with fewer repeats (HR for BRCA1/2 carriers = 0.88, 95% CI [confidence interval] = 0.75-1.04). Analyzing average repeat lengths as a continuous variable showed no excess risk of breast cancer (BC) in BRCA1 or BRCA2 mutation carriers (HR for average repeat length in BRCA1/2 carriers = 1.01, 95% CI = 0.92-1.11). These results strongly suggest that contrary to previous studies, there is no significant effect of AIB1 genetic variation on BC risk in BRCA1 mutation carriers and provide an indication that there is also no strong risk modification in BRCA2 carriers.
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2,337,550 |
Association between the COMT Val158Met polymorphism and propensity to anxiety in an Australian population-based longitudinal study of adolescent health.
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Catechol-O-methyltransferase plays a central role in the metabolism of biogenic amines such as norepinephrine, dopamine and serotonin. Functional studies have demonstrated a dose relationship between ValMet genotypes and catechol-O-methyltransferase activity. Compared with the ValVal genotype, the ValMet and MetMet genotypes result in two- and four-fold reductions in catechol-O-methyltransferase activity, respectively. Two recent reports have observed the association between the MetMet genotype and risk of anxiety in adult populations. We examined the association between the ValMet genotypes and propensity to anxiety across adolescence.</AbstractText>Participants were drawn from an eight-wave study of the mental and behavioural health of over 2000 young Australians followed from 14 to 24 years of age (Victorian Adolescent Health Cohort Study, 1992 to present). DNA was received from 962 participants using a cheek swab collection method.</AbstractText>The odds of reporting persistent episodic anxiety (phobic avoidance, panic attacks) were doubled among carriers of the MetMet genotype (odds ratio 2.0, 95% confidence interval 1.1-3.4, P=0.014). A dose relationship between additional copies of the Met allele and persistent episodic anxiety was also observed (1.5, 1.1-1.94, P=0.007). Stratification by sex showed that the risk effect of the Met allele was among females only. No association was observed for measures of neuroticism, persistent generalized anxiety, or a composite measure of psychiatric distress.</AbstractText>These data replicate previous findings suggesting association between the ValMet polymorphism and specific expressions of anxiety among females.</AbstractText>
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2,337,551 |
Extracellular superoxide dismutase (EC-SOD) gene mutations screening in a sample of Mediterranean population.
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The main role of superoxide dismutases (SODs) is to eliminate reactive oxygen species in cells and tissues. Extracellular SOD (EC-SOD/SOD3) is a major superoxide scavenger and it is located on cell surfaces and primarily in extracellular matrix, and binds heparan sulfates by its carboxyterminal portion. Human EC-SOD gene is located on chromosome 4 and comprises three exons and two introns. The SOD3 coding sequence is entirely located within exon 3 and has missense polymorphisms. The Arg213Gly mutation affects the function of the carboxyterminus and correlates with several diseases. In this work, we explored genetic variants within EC-SOD gene of subjects living in southern Italy. Four new variations were detected: one was silent mutation, while three were missense variations that give rise to amino acid substitutions at position 131 (F>C), 160 (V>L) and 202 (R>L) in the mature product. The Arg213Gly variant was not found. The missense mutations in the DNA of assayed 2400 chromosomes had frequencies of 5.34% for the F131C variation, 0.25% for the V160L variation and 0.84% for the R202L variation. The effect of these alterations on the metabolic activity and diseases remains to be further explained.
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2,337,552 |
Decreased levels of BDNF protein in Alzheimer temporal cortex are independent of BDNF polymorphisms.
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Levels of brain-derived neurotrophic factor (BDNF) are reduced in specific brain regions in Alzheimer's disease (AD) and BDNF gene polymorphisms have been suggested to influence AD risk, hippocampal function, and memory. We investigated whether the polymorphisms at the BDNF 196 and 270 loci were associated with AD in a clinical and neuropathological cohort of 116 AD cases and 77 control subjects. To determine how BDNF protein levels relate to BDNF polymorphisms and AD pathology, we also measured BDNF in temporal association cortex, frontal association cortex, and cerebellum in 57 of the AD and 21 control cases. BDNF protein levels in temporal neocortex of the AD brains were reduced by 33% compared to control brains, whereas levels were unchanged in frontal and cerebellar cortex. The BDNF genotypes were not significantly associated with a diagnosis of AD, although the BDNF 270 C allele was slightly overrepresented among carriers of the APOEepsilon4 allele. Moreover, BDNF protein levels did not differ between the various BDNF genotypes and alleles. Neuropathologically, the loss of BDNF in AD showed a weak correlation with accumulation of neuritic amyloid plaques and loss of the neuronal/synaptic marker synaptophysin. The results suggest that the investigated BDNF polymorphisms are neither robust genetic risk factors nor determinants of BDNF protein levels in AD.
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2,337,553 |
Evaluation of hereditary risk in a mammography population.
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BRCA1 and BRCA2 mutations significantly increase a women's lifetime risk of breast and ovarian cancer. Because several management options have shown promise in decreasing morbidity and mortality for these women, identifying potential mutation carriers is increasingly important. We have developed a large-scale method to collect family histories in a population of unaffected women presenting for mammography. We then applied current risk-assessment models to determine the prevalence of women at risk for hereditary breast and ovarian cancer.</AbstractText>We performed a retrospective review of family histories using data collected on all unaffected women presenting for mammography over a 14-week period. The Claus, Myriad II, and Hartmann models for hereditary risk assessment were applied to the survey results.</AbstractText>The questionnaire was completed by 5736 women, 695 of whom were excluded because of a personal history of breast or ovarian cancer. Family histories of the remaining 5041 women were evaluated. Totals of 5.9%, 5.2%, and 3.3% of patients, respectively, met criteria for increased risk according to the Hartmann, Myriad II, and Claus models, corresponding to 3.5, 3.1, and 1.9 patients per day. Although 9.2% of patients met criteria for >/=1 model, only 1.4% met criteria for all 3.</AbstractText>Application of available models to a screening population classifies a larger than expected number of women at high risk for a BRCA1 or BRCA2 mutation. New approaches to risk assessment and counseling are needed to apply our knowledge of hereditary risk to a broad population in a practical manner.</AbstractText>
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2,337,554 |
Development of polymer latex particles for selective cleavage of mismatched DNA and their application for DNA diagnosis.
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We developed functional polymer latex particles that can catch and cleave mismatched DNA selectively and propose a new mismatch detection system using the functional particles. The aimed particles possess two functional units composed of mismatch binding protein (MutS) and an anthraquinone derivative (AQ), a light-activated agent that photocleaves dsDNA. Use of the functional particles made it possible to discriminate complementary and mismatched DNAs and photocleave mismatched DNA selectively. The efficiency of photocleavage of mismatched DNA by the functional particles increased with UV irradiation time. It was also found that the functional particles were reusable and had dissociation constants (K(d)) of 1000 and 68.5 nM for G/C homoduplex and G/T heteroduplex, respectively. Using the functional particles and a dsDNA-binding fluorescent dye, SYBR-Gold, we could construct the system for detection of mismatched DNA that was 40 base pairs. The functional particles prepared in this study will be an absolutely new tool for mismatch detection in DNA diagnosis.
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2,337,555 |
Identification of candidate regions for familial idiopathic scoliosis.
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A genomic screen and statistical linkage analysis of 202 families with at least two individuals with idiopathic scoliosis was performed.</AbstractText>To identify candidate regions or the autosomal loci that may be involved in the expression of familial idiopathic scoliosis.</AbstractText>A large sample of families with individuals having idiopathic scoliosis (202 families; 1,198 individuals) was ascertained; diagnoses were based on physical examination and radiographic criteria.</AbstractText>Model-independent linkage analysis of qualitative and quantitative traits (degree of lateral curvature) related to scoliosis was used to screen genotyping data from 391 markers in the 202 families. Subsets of families were determined before genotyping based on the most likely mode of inheritance for each family (autosomal dominant vs. X-linked dominant). Fine mapping results corroborated linkage in the primary candidate regions.</AbstractText>Candidate regions on chromosomes 6, 9, 16, and 17 were considered to have the strongest evidence for linkage across all subsets considered.</AbstractText>Linkage analyses have identified several candidate regions, a significant step in defining the genetic etiology of this disorder.</AbstractText>
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2,337,556 |
Significance of Beevor's sign in facioscapulohumeral dystrophy and other neuromuscular diseases.
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An atypical presentation of facioscapulohumeral dystrophy (FSH) is described, where the presence of a positive Beevor's sign led to genetic testing and subsequent probable diagnostic confirmation. This prompted evaluation of a further 68 patients for the presence of Beevor's sign. Among these, 19/20 patients with FSH had a positive Beevor's sign, compared with 2/28 with other muscle diseases, and 0/20 in a neurological control group. Beevor's sign should be considered as an additional criterion for the diagnosis of FSH.
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2,337,557 |
A study of TRAIL receptors in squamous cell carcinoma of the head and neck.
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To determine the potential immediate applicability of tumor necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) and TRAIL-R2, the apoptotic forms of TRAIL-Rs, for preclinical testing.</AbstractText>Head and neck squamous cell carcinoma (HNSCC) tumors were studied for TRAIL-R1 and TRAIL-R2 expression by immunohistochemical analysis. In addition, matched tumor and peripheral blood DNA samples were screened for 2 known TRAIL-R1 coding single nucleotide polymorphisms (C626G and G422A). Subjects Tumor samples taken from 43 patients (37 samples for immunohistochemical analysis and 6 additional ones included for polymorphism analysis).</AbstractText>The expression of TRAIL-R1 and TRAIL-R2 and the presence of the TRAIL-R1 polymorphisms C626G and G422A.</AbstractText>Fewer than 25% of HNSCC tumor cells expressed TRAIL-R1 and TRAIL-R2. Surrounding tumor-infiltrating polymorphonuclear cells expressed TRAIL-R1 and TRAIL-R2 in 12 (32%) and 14 (38%) of cases, respectively. The TRAIL-R1 polymorphisms C626G and G422A were present in 36 (88%) and 33 (89%) cancer cases, respectively. Compared with control groups from another study, these polymorphism frequencies were statistically significant (P = .01 and .003, respectively).</AbstractText>TRAIL-R expression was detected in less than half of the tumor specimens studied but not in any surrounding normal tissue and was found in a higher frequency on tumor-infiltrating polymorphonuclear cells than on tumor cells. These findings support the idea that the presence of TRAIL-Rs on some HNSCC tumors may make them more susceptible to apoptosis, and they also suggest that TRAIL-R-associated mechanisms may result in immune-modulatory effects on tumor-infiltrating polymorphonuclear cells. Furthermore, the significant association of somatic TRAIL-R1 genetic polymorphisms in this sample of patients with HNSCC suggests a potential association between constitutive TRAIL-R1 polymorphisms and development of HNSCC. Defining TRAIL-R expression and genetic polymorphisms in HNSCC represents the first step in examining TRAIL-related mechanisms for their potential as therapeutic targets.</AbstractText>
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2,337,558 |
Fibroblast growth factor receptor 3 inhibition by short hairpin RNAs leads to apoptosis in multiple myeloma.
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The presence of t(4;14)(p16.3;q32.3) in multiple myeloma cells results in dysregulated expression of the fibroblast growth factor receptor 3 (FGFR3). FGFR3 acts as an oncogene to promote multiple myeloma cell proliferation and antiapoptosis. These encourage the clinical development of FGFR3-specific inhibitors. Three short hairpin RNAs (shRNA) targeting different sites of FGFR3 were selected and subsequently transfected into KMS-11, OPM-2, and NCI-H929 human myeloma cell lines, all of which are characterized by t(4;14) and FGFR3 over expression. The combination of these three shRNAs can effectively inhibit FGFR3 expression in all three cell lines. Sequential immunocytochemistry/fluorescence in situ hybridization was employed to validate that the shRNAs specifically inhibited FGFR3 expression in OPM-2 cells. Decreased expression of B-cell chronic lymphocytic leukemia/lymphoma 2 (BCL2) and myeloid cell leukemia sequence 1 (MCL1) proteins and increased staining of Annexin V-positive cells showed that inhibition of FGFR3 induces apoptosis. After confirming down-regulation of FGFR3 by real-time PCR, HU-133 plus 2.0 array was employed to compare the gene expression profile of shRNA-treated sample with that of the control. Besides the down-regulation of FGFR3, expression of the antiapoptotic genes CFLAR, BCL2, MCL1, and some members of NF-kappaB family decreased, whereas expression of the proapoptotic genes CYC, BID, CASP2, and CASP6 increased. Microarray results also revealed changes in genes previously implicated in multiple myeloma pathogenesis (RAS, RAF, IL-6R, and VEGF), as well as others (TLR4, KLF4, and GADD45A) not previously linked to multiple myeloma. Our observations indicate that shRNAs can specifically and effectively inhibit FGFR3 expression. This targeted approach may be worth testing in multiple myeloma patients with t(4;14) and FGFR3 overexpression in the future.
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2,337,559 |
Prenatal diagnostic decision-making in adolescents.
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We sought to evaluate the prenatal decision-making of pregnant adolescents identified at increased risk for identifiable fetal genetic abnormalities.</AbstractText>A retrospective review of records of gravid women 19 years old or younger undergoing genetic counseling from 2001-2003 (inclusive) was undertaken.</AbstractText>Hospital-based academic center.</AbstractText>Thirty-seven women were identified; four cases did not meet inclusion criteria.</AbstractText>None.</AbstractText>Decision to undergo or forgo invasive prenatal testing.</AbstractText>Of the 33 women included in this study, the average age was 17.6 years (range: 15-19). Eighteen were Latinas, eight were African-Americans, and seven were Caucasians. Sixteen women had positive maternal serum screening outcomes; nine women sought counseling because of personal/family histories of genetic abnormalities, seven sought counseling after fetal structural anomalies were detected by ultrasound, and one woman sought counseling because she and her partner were positive for Mendelian disorder screening (sickle cell disease). Sixteen of the women (48.5%) chose to undergo invasive testing (15 amniocenteses, one chorionic villus sampling) whereas 17 (51.5%) chose to forgo invasive testing.</AbstractText>Adolescents offered invasive prenatal diagnosis will chose to undergo or forgo such testing based on diagnostic and personal criteria as do adult women. Nonetheless, unique adolescent issues may make the process by which information is obtained and communicated during counseling to be different from counseling provided to adults. The development of new genetic screening and diagnostic protocols has and will increase the number of pregnant adolescent women who will be offered genetic counseling during their pregnancies. Such an increase in numbers will place considerably more pressure on an already taxed genetic counseling system; accordingly, new counseling paradigms will need to be developed to provide service to an expanded patient population seeking information for an increasing number of genetic issues.</AbstractText>
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2,337,560 |
Clinical evaluation and mitochondrial DNA sequence analysis in three Chinese families with Leber's hereditary optic neuropathy.
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We report here the clinical, genetic, and molecular characterization of three Chinese families (WZ4, WZ5, and WZ6) with Leber's hereditary optic neuropathy (LHON). Clinical and genetic evaluations revealed the variable severity and age-of-onset in visual impairment in these families. Penetrances of visual impairment in these Chinese families were 33.3%, 35.7%, and 35.5%, respectively, with an average 34.8%. Furthermore, the average age-at-onset in those Chinese families was 17, 20, and 18 years. In addition, the ratios between affected male and female matrilineal relatives in these Chinese families were 3:0, 1:1, and 1.2:1, respectively. Sequence analysis of the complete mitochondrial genomes in these pedigrees showed the distinct sets of mtDNA polymorphism, in addition to the identical G11778A mutation associated with LHON in many families. The fact that mtDNA of those pedigrees belonged to different haplogroups F1, D4, and M10 suggested that the G11778A mutation occurred sporadically and multiplied through evolution of the mtDNA in China. However, there was the absence of functionally significant mutations in tRNA and rRNAs or secondary LHON mutations in these Chinese families. The I187T mutation in the ND1, the S99A mutation in the A6, the V254I in CO3, and I58V in ND6 mutation, showing high evolutional conservation, may contribute to the phenotypic expression of the G11778A mutation in the WZ6 pedigree. By contrast, none of mtDNA variants are evolutionarily conserved and implicated to have significantly functional consequence in WZ4 and WZ5 pedigrees. Apparently, these variants do not have a potential modifying role in the development of visual impairment associated with G11778A mutation in those two families. Thus, nuclear modifier gene(s) or environmental factor(s) seem to account for the penetrance and expressivity of LHON in these three Chinese families carrying the G11778A mutation.
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2,337,561 |
Characterization of a novel HLA-Cw*02 variant, Cw*0208, in a Caucasian individual.
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We describe an additional HLA-Cw*02 variant, HLA-Cw*0208, which has been identified in a renal transplant recipient of Caucasian origin (Italy). After performing preliminary serological typing, we analyzed exons 2 and 3 of the HLA-C locus polymorphism by cloning the amplified DNA and using a sequence-based typing method. The new allele differs from Cw*020202 by one nucleotide substitution at nucleotide 61 (G-->A) of exon 2, which translates to a difference of one amino acid at residue 21 (His-->Arg) of the HLA-C heavy chain. We propose that Cw*0208 was generated by a random point mutation in codon 21 from the Cw*020202 allele, or through gene conversion of Cw*020202 with another allele, probably the Cw*1205 and Cw*1602 alleles.
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2,337,562 |
HLA-B*5701 typing by sequence-specific amplification: validation and comparison with sequence-based typing.
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Susceptibility to abacavir hypersensitivity (ABC HSR) is strongly associated with alleles carried on the 57.1 ancestral haplotype including HLA-B*5701 and Hsp70 Hom M493T. In one study, prospective testing for HLA-B*5701 and exclusion of individuals carrying this allele, from receiving abacavir, substantially lowered the incidence of ABC HSR to 0% (95% confidence interval 0-0.075%). The presence of HLA-B*5701 is usually detected by standard serological tests and by molecular genetic methods such as sequence-based typing (SBT). While the former test cannot discriminate between HLA-B57 subtypes, the expensive SBT may not be readily available in all laboratories. Hence, an alternate method was developed to detect HLA-B*5701 using allele and group-specific polymerase chain reaction-sequence-specific primers (PCR-SSP) typing. This PCR-SSP-typing method positively amplified all HLA-B*5701 alleles in concordance with their SBT-assigned typing. This multiplexed SSP assay was able to distinguish between HLA-B*5701 (n = 10) and closely related HLA-B57 alleles B*5702 (n = 2), -B*5703 (n = 1), -B*5704 (n = 1) alleles and non-HLA-B*57 alleles (n = 61). In conclusion, this method of HLA-B*5701 detection is a rapid and accurate typing method with high specificity, sensitivity and reproducibility.
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2,337,563 |
[Distribution of haplotypes for four Y-sTR loci and validation in forensic science by using a double-fluorescent multiplex PCR system].
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We focus on developing a multiplex PCR system for Y-STR loci that can be detected by double fluorescent system and assessing their usefulness in forensic mixture samples.</AbstractText>The primers of four Y-STR loci (DYS-GATA-A10, DYS531, DYS557 and DYS448) amplified by multiplex PCR technique were labeled with fluorescence, then the PCR products of these Y-STRs loci were detecting and typing by ABI PRISM310 Genetic Analyzer.</AbstractText>When 120 unrelated individuals from the Han population in Chengdu were detected by the system, Y-GATA-A10, DYS531, DYS557 and DYS448 showed 5, 5, 8, 7 alleles, respectively. A total of 78 different haplotypes was identified and the genetic diversity reached 0.9881. To the three cases of mixture stains failed by using conventional autosomal STR analysis, our multiplex system drew conforming conclusion comparing to the suspect's Y-STRs genotypes.</AbstractText>Our results show that the multiplex system of four Y-STR will be very powerful for Y-STR database establishing, the paternity testing and mixture stains identifying.</AbstractText>
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2,337,564 |
The wide spectrum of spinocerebellar ataxias (SCAs).
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Spinocerebellar ataxias (SCAs) are a clinically heterogeneous group of disorders. Current molecular classification corresponds to the order of gene description (SCA1-SCA 25). The prevalence of SCAs is estimated to be 1-4/100,000. Patients exhibit usually a slowly progressive cerebellar syndrome with various combinations of oculomotor disorders, dysarthria, dysmetria/kinetic tremor, and/or ataxic gait. They can present also with pigmentary retinopathy, extrapyramidal movement disorders (parkinsonism, dyskinesias, dystonia, chorea), pyramidal signs, cortical symptoms (seizures, cognitive impairment/behavioral symptoms), peripheral neuropathy. SCAs are also genetically heterogeneous and the clinical diagnosis of subtypes of SCAs is complicated by the salient overlap of the phenotypes between genetic subtypes. The following clinical features have some specific values for predicting a gene defect: slowing of saccades in SCA2, ophthalmoplegia in SCA1, SCA2 and SCA3, pigmentary retinopathy in SCA7, spasticity in SCA3, dyskinesias associated with a mutation in the fibroblast growth factor 14 (FGF 14) gene, cognitive impairment/behavioral symptoms in SCA17 and DRPLA, seizures in SCA10, SCA17 and DRPLA, peripheral neuropathy in SCA1, SCA2, SCA3, SCA4, SCA8, SCA18 and SCA25. Neurophysiological findings are compatible with a dying-back axonopathy and/or a neuronopathy. Three patterns of atrophy can be identified on brain MRI: a pure cerebellar atrophy, a pattern of olivopontocerebellar atrophy, and a pattern of global brain atrophy. A remarkable observation is the presence of dentate nuclei calcifications in SCA20, resulting in a low signal on brain MRI sequences. Several identified mutations correspond to expansions of repeated trinucleotides (CAG repeats in SCA1, SCA2, SCA3, SCA6, SCA7, SCA17 and DRPLA, CTG repeats in SCA8). A pentanucleotide repeat expansion (ATTCT) is associated with SCA10. Missense mutations have also been found recently. Anticipation is a main feature of SCAs, due to instability of expanded alleles. Anticipation may be particularly prominent in SCA7. It is estimated that extensive genetic testing leads to the identification of the causative gene in about 60-75 % of cases. Our knowledge of the molecular mechanisms of SCAs is rapidly growing, and the development of relevant animal models of SCAs is bringing hope for effective therapies in human.
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2,337,565 |
Gastric cancer: new genetic developments.
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Gastric cancer's (GC) incidence shows large geographic differences worldwide with the lowest rates occurring in most Western industrialized countries including the United States and the United Kingdom; in contrast, relatively high rates of GC occur in Japan, Korea, China, and South America, particularly Chile. The Laurén classification system classifies GC under two major histopathological variants: 1) an intestinal type and 2) a diffuse type. The intestinal type is more common in the general population, more likely to be sporadic and related to environmental factors such as diet, particularly salted fish and meat as well as smoked foods, cigarette smoking, and alcohol use. It exhibits components of glandular, solid, or intestinal architecture, as well as tubular structures. On the other hand, the diffuse type is more likely to have a primary genetic etiology, a subset of which, known as hereditary diffuse gastric cancer (HDGC), is due to the E-cadherin (CDH1) germline mutation. The diffuse type pathology is characterized by poorly cohesive clusters of cells which infiltrate the gastric wall, leading to its widespread thickening and rigidity of the gastric wall, known as linitis plastica. Helicobacter pylori infection is associated with risk for both the intestinal and diffuse varieties of gastric cancer. Germline truncating mutations of the CDH1 gene, which codes for the E-cadherin protein, were initially identified in three Maori families from New Zealand that were predisposed to diffuse GC. Since then, similar mutations have been described in more than 40 additional HDGC families of diverse ethnic backgrounds. It is noteworthy that two-thirds of HDGC families reported to date have proved negative for the CDH1 germline mutation. A number of candidate genes have been identified through analysis of the molecular biology of E-cadherin. Patients with evidence of the CDH1 germline mutation in the context of a family history of HDGC must be considered as candidates for prophylactic gastrectomy, given the extreme difficulty in its early diagnosis and its exceedingly poor prognosis when there is regional or distant spread. Specifically, the E-cadherin cytoplasmic tail interacts with catenins, assembling the cell-adhesion complex involved with E-cadherin mediated cell:cell adhesion. Beta-catenin and gamma-catenin compete for the same binding site on the E-cadherin cytoplasmic tail, directly linking the adhesion complex to the cytoskeleton through alpha-catenin. Beta-catenin gene (CTNNB1) mutations have been described predominantly in intestinal-type gastric cancers and CTNNB1 gene amplification and overexpression have recently been described in a mixed-type gastric cancer. This paper reviews the genetics of both intestinal and diffuse types of gastric carcinoma, their differential diagnosis, molecular genetics, pathology, and, when known, their mode of genetic transmission within families.
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2,337,566 |
Alpha-synuclein and Parkinson's disease: implications from the screening of more than 1,900 patients.
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Data on the frequency of alpha-synuclein mutations in Parkinson's disease (PD) are limited. Screening the entire coding region in 1,921 PD patients with denaturing high performance liquid chromatography and subsequent sequencing we only detected silent mutations (g.2654A>G, g.10151G>A, and g.15986A>T) and the c.209G>A substitution corresponding to the p.A53T mutation. These results demonstrate that mutations in the alpha-synuclein gene are rare and suggest that other factors contribute to alpha-synuclein aggregation in the majority of PD patients.
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2,337,567 |
Genetic testing and the family.
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The family experience of genetic testing is explored in this article. Two family stories are presented to illustrate how families define and manage the ethical and social issues that emerge during 2 types of genetic testing: mutation analysis for Huntington's disease and genetic testing for breast and ovarian cancer susceptibility. These 2 families were purposefully selected because their stories exemplify the complexity of the genetic testing experience. In addition, the story of the family living with Huntington's disease shows how negative consequences can occur for the individual tested, other family members, the marital relationship, and the family system, even when the test results indicate that the individual does not carry a deleterious gene mutation. Both of the families presented in this article participated in an ongoing study, Family Experience of Genetic Testing: Ethical Dimensions , in which 118 family members from 67 families have participated. The guiding framework for this research was the family management style framework developed and refined by Knafl and colleagues.
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2,337,568 |
Newborn screening and genetic testing.
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New screening techniques and diagnostic tests for genetic diseases available for newborn screening can provide information about many diseases long before they are clinically detected. However, this information creates complex questions and ethical dilemmas regarding which newborns should be tested, when testing should occur, availability and costs of tests, and how families should be counseled. There is no national policy regarding newborn screening, which leads to great variation among states' newborn screening programs. This article reviews newborn genetic testing and provides a blueprint for clinicians to improve practice by incorporating into their care knowledge of new developments in newborn testing and screening.
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2,337,569 |
Options for Down syndrome screening: what will women choose?
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Down syndrome screening has been offered to pregnant women since the early 1980s. Protocols have changed as research confirmed improvements that result in higher detection rates and lower false-positive rates. Results from 2 clinical trials evaluating screening protocols that include ultrasound measurement of nuchal translucency and biochemical testing in the first and second trimester are now available. First-trimester screening is an option if there are adequate ultrasound, diagnostic, and counseling services available. Regional variation in the availability of these services may limit the implementation of first-trimester screening. Combining screening tests for Down syndrome from both trimesters as an integrated test offers the highest detection rate with the lowest false-positive rate. The possibility of avoiding a positive screen will make this an attractive option for some. Timing, detection rate, false-positive rates, and personal factors influence the decision women make regarding screening versus diagnostic testing. This article reviews the efficacy of current protocols for Down syndrome screening. Accurate information about available screening tests will facilitate informed decisions about screening and testing.
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2,337,570 |
Cystic fibrosis screening.
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The integration of universal cystic fibrosis screening in women's health has considerably altered the way we care for obstetric patients and likely will be the foundation for incorporating other genetic tests into routine women's health care. Prior to this change in the standard of care, screening for genetic disease was primarily limited to those individuals who had a personal or family history of the genetic condition or who belonged to a particular ethnic or racial group characterized by a high frequency of carrier and affected individuals. However, technological advances have resulted in facile and economic methodologies for detecting an increasing number of genetic mutations and in the realization that screening for common and uncommon disorders will likely be a not-too-distant-future part of routine health care. Programs that permit clinicians to properly implement genetic protocols and allow patients to make informed decisions about genetic screening and diagnostic tests are needed. The implementation of universal cystic fibrosis screening allows clinicians to recognize the benefits and pitfalls of genetic testing of the general population and encourages the development of programs that will effectively communicate genetic information to professionals and laity.
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2,337,571 |
A primer on genetic testing.
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Use of genetic tests in the clinical practice setting is a current reality, and an increasing number of patients are asking about and requesting genetic testing. The push to translate genetic research findings and technological innovations into clinical practice will continue as our understanding of the genetic basis of disease increases. Special consideration is required when ordering genetic tests, beyond that of other laboratory tests, and an understanding of the unique aspects involved will help optimize clinical outcomes. The purpose of this primer is to provide a basic understanding of genetic testing, discuss current issues related to the use of tests, and outline practical steps for critically using genetic tests in clinical practice.
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2,337,572 |
Genetic competencies essential for health care professionals in primary care.
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The completion of the sequencing of the human genome in 2003 signaled the onset of the genomic era in health care. The knowledge gleaned from the Human Genome Project has led to the understanding that every health problem has a genetic component and that clinicians should include the application of genetic information in all aspects of health care. This article describes the genetic competencies essential for all health care professionals in primary care. Health care professionals should augment their current practice by obtaining a multigenerational genetic family history for each patient, assessing all patients for potentially heritable conditions, providing referrals to genetic health professionals as needed, offering genetic testing when indicated, and considering an individual's genetic makeup in the selection of medications and treatments for that person. Finally, all health care professionals ought to be prepared to address the complex personal, cultural, theological, ethical, legal, and social issues associated with genetic testing and other genetic issues commonly encountered in clinical practice.
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2,337,573 |
A novel germline mutation, 1793delG, of the MEN1 gene underlying multiple endocrine neoplasia type 1.
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Pulmonary carcinoids are rare neuroendocrine tumors which comprise 1-2% of all lung tumors. They usually occur sporadically; however, their association with multiple endocrine neoplasia type 1 (MEN1) syndrome has been documented. We report a case of a Thai woman with a pulmonary carcinoid tumor and a null cell pituitary tumor. Her family history was unremarkable for any MEN-related lesions. Genetic testing revealed a novel deletion mutation at exon 10 (1793delG) of the MEN1 gene, resulting in a stop codon 26 amino acids downstream. This mutation is predicted to cause a loss of the second nuclear localization signal of the menin protein.
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2,337,574 |
Screening for deleterious nonsynonymous single-nucleotide polymorphisms in genes involved in steroid hormone metabolism and response.
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To facilitate selection of single-nucleotide polymorphisms (SNP) for molecular epidemiologic studies investigating the hormonal carcinogenesis hypothesis, we used two sequence homology-based tools [Sort Intolerant from Tolerant (SIFT) and Polymorphism Phenotype (PolyPhen)] to predict the potential impact a nonsynonymous SNP (nsSNP), which results in an amino acid substitution, may have on the activity of proteins encoded by genes involved in the steroid hormone metabolism and response pathway. We screened 137 variants. Of these, 28% were predicted by SIFT and PolyPhen as having a potentially damaging effect on protein function. Investigation into the association of these variant alleles with hormone-related cancers may prove to be fruitful.
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2,337,575 |
Deletion of iNOS gene impairs mouse fracture healing.
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Nitric oxide (NO) is a signaling molecule synthesized from l-arginine by nitric oxide synthases (NOSs). NOS isoforms are either constitutive (endothelial NOS [eNOS] and neuronal NOS [nNOS]) or inducible NOS (iNOS). Previously, our group has reported that NO is expressed during and modulates fracture healing. In this study, we evaluated the specific contribution of iNOS to fracture healing by using iNOS gene therapy in iNOS-deficient mice. Twelve-week-old female wild-type mice and iNOS-KO mice had a right femoral midshaft osteotomy fixed with an intramedullary 0.5-mm-diameter needle. A gelatine sponge was implanted across the fracture site. The gelatine sponge received either Ad5-CMViNOS (in iNOS-deficient mice; n=16) or Ad5-CMVempty (in wild-type mice; n=15, and iNOS-deficient mice; n=15) at a dose of 10(7) pfu. Mice were sacrificed at day 14, and their right and left hind limbs were harvested. Cross-sectional area (CSA) was determined by measuring the callus diameter across the mediolateral and anteroposterior plane using a vernier caliper. Specimens were loaded to failure torsionally in a biaxial INSTRON testing system, and maximum torque, torsional stiffness, and maximal and total energy were determined. Deletion of the iNOS gene decreased the total and maximum energy absorption of the healing femoral fracture by 30% and by 70% (P<0.01), respectively, in comparison to the wild-type mice. This reduction in energy absorption was reversed by iNOScDNA administration via adenovirus vector. Furthermore, iNOScDNA caused an increase in torsional failure by 20% (P=0.01) in comparison to iNOS(-/-) mice that did not receive the iNOScDNA. There were no significant differences in the biomechanical properties of intact femora. These data indicate that iNOS is important in mouse fracture healing. However, the clinical utility of NOS gene therapy to enhance fracture healing will need further evaluation.
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2,337,576 |
On statistical tests of phylogenetic tree imbalance: the Sackin and other indices revisited.
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We investigate the distribution of statistical measures of tree imbalance in large phylogenies. More specifically, we study normalized versions of the Sackin's index and the number of subtrees of given sizes. Using the connection with structures from theoretical computer science, we provide precise description for the limiting distribution under the null hypothesis of Yule trees. Corrected p-values are then computed, and the statistical power of these statistics for testing the Yule model against a model of biased speciation is evaluated from simulations. As an illustration, the tests are applied to the HIV-1 reconstructed phylogeny.
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2,337,577 |
The decision evaluation scales.
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There are several instruments to assess how patients evaluate their medical treatment choice. These are used to evaluate decision aids. Our objective is to investigate which psychological factors play a role when patients evaluate their medical treatment choices. A pool of 36 items was constructed, covering concepts such as uncertainty about and satisfaction with the decision, informed choice, effective decision making, responsibility for the decision, perceived riskiness of the choice, and social support regarding the decision. This pool was presented to patients at high risk for breast and ovarian cancer, awaiting a genetic test result, and facing the choice between prophylactic surgery or screening. Additional measures were assessed for validation purposes. Factor and Rasch analyses were used for factor and item selection. Construct validity of emerging scales was assessed by relating them with the additional measures. Three factors summarised the psychological factors concerning decision evaluation: Satisfaction-Uncertainty, Informed Choice, and Decision Control. Reliabilities (Cronbach's alpha) of the three scales were 0.79, 0.85, and 0.75, respectively. Construct validity hypotheses were confirmed. The first two scales were similar to previously developed scales. Of these three scales, the Decision Control scale correlated most strongly with the well-being measures, was associated with partner's agreement and physician's preferences as perceived by patients, and with a negative emotional reaction to the information material. In conclusion, the Decision Control scale is a new scale to evaluate decision aids, and it appears to be rooted in health psychological theories.
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2,337,578 |
The catadromous European eel Anguilla anguilla (L.) as a model for freshwater evolutionary ecotoxicology: relationship between heavy metal bioaccumulation, condition and genetic variability.
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Understanding the effects of pollutants on the genome is of crucial importance to preserve the evolutionary potential of endangered natural populations. The highly vagile European eel (Anguilla anguilla L.) has suffered a dramatic decline in recruitment since two decades, urging for a better understanding of the genetic impact of pollution. Its catadromous life history constitutes a model to assess local selection of pollutants on condition and genetic variability, as juveniles recruit in European rivers without appreciable pollution load or interfering genetic background. Because of its high fat content and local benthic feeding behaviour, the feeding stage is considered extremely prone to the bioaccumulation of pollutants. We studied the relationship between heavy metal bioaccumulation, fitness (condition) and genetic variability in the European eel. The muscle tissues of 78 sub-adult eels, originating from three Belgian river basins (Scheldt, Meuse and Yser), were examined for nine heavy metal pollutants (Hg, Cd, Pb, Cu, Zn, Ni, Cr, As and Se), while in total 123 individuals were genotyped at 12 allozyme and 8 microsatellite loci. A significant negative correlation between heavy metal pollution load and condition was observed, suggesting an impact of pollution on the health of sub-adult eels. In general, we observed a reduced genetic variability in strongly polluted eels, as well as a negative correlation between level of bioaccumulation and allozymatic multi-locus heterozygosity (MLH). Microsatellite genetic variability did not show any pollution related differences, suggesting a differential response at metabolic enzymes and possibly direct overdominance of heterozygous individuals.
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2,337,579 |
Enhanced functional recovery from spinal cord injury following intrathecal or intramuscular administration of poliovirus replicons encoding IL-10.
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Poliovirus-based vectors (replicons) have been shown to maintain the in vitro tropism of poliovirus for motor neurons of the CNS. To determine if replicons could be effective for delivery of potentially beneficial proteins to the CNS, we have constructed and characterized a replicon encoding IL-10. IL-10 was rapidly produced in tissue culture cells following in vitro infection with replicons encoding IL-10. Intrathecal inoculation of replicons encoding IL-10 into the non-injured CNS of mice transgenic for the poliovirus receptor resulted in expression of IL-10 within motor neurons at 24-48 h post-inoculation, which subsided by 72-96 h post-inoculation. Single intrathecal or intramuscular injections of replicons were given following spinal cord trauma. Animals receiving replicons encoding IL-10 demonstrated a greater functional recovery in the first 24 h after injury that was maintained throughout the testing period. Compared to animals given replicons encoding gfp, CNS tissue from animals given replicons encoding IL-10 revealed extensive expression of IL-10 from astrocytes around the CNS lesion during the first week following injury. The expression of IL-10 from astrocytes also correlated with more resting microglia as opposed to the rounded activated microglia seen in animals given replicons encoding gfp. Results of these studies establish that replicons can be used to express biologically active molecules in motor neurons of the CNS and these biologically active molecules can have a direct effect on the CNS or induce a cascade of molecules that can influence the cellular composition and activation state of cells within the CNS.
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2,337,580 |
Phenotypic and genetic differentiation between native and introduced plant populations.<Pagination><StartPage>1</StartPage><EndPage>11</EndPage><MedlinePgn>1-11</MedlinePgn></Pagination><Abstract><AbstractText>Plant invasions often involve rapid evolutionary change. Founder effects, hybridization, and adaptation to novel environments cause genetic differentiation between native and introduced populations and may contribute to the success of invaders. An influential idea in this context has been the Evolution of Increased Competitive Ability (EICA) hypothesis. It proposes that after enemy release plants rapidly evolve to be less defended but more competitive, thereby increasing plant vigour in introduced populations. To detect evolutionary change in invaders, comparative studies of native versus introduced populations are needed. Here, we review the current empirical evidence from: (1) comparisons of phenotypic variation in natural populations; (2) comparisons of molecular variation with neutral genetic markers; (3) comparisons of quantitative genetic variation in a common environment; and (4) comparisons of phenotypic plasticity across different environments. Field data suggest that increased vigour and reduced herbivory are common in introduced plant populations. In molecular studies, the genetic diversity of introduced populations was not consistently different from that of native populations. Multiple introductions of invasive plants appear to be the rule rather than the exception. In tests of the EICA hypothesis in a common environment, several found increased growth or decreased resistance in introduced populations. However, few provided a full test of the EICA hypothesis by addressing growth and defence in the same species. Overall, there is reasonable empirical evidence to suggest that genetic differentiation through rapid evolutionary change is important in plant invasions. We discuss conceptual and methodological issues associated with cross-continental comparisons and make recommendations for future research. When testing for EICA, greater emphasis should be put on competitive ability and plant tolerance. Moreover, it is important to address evolutionary change in characteristics other than defence and growth that could play a role in plant invasions.</AbstractText></Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Bossdorf</LastName><ForeName>Oliver</ForeName><Initials>O</Initials><AffiliationInfo><Affiliation>Department of Community Ecology, UFZ-Centre for Environmental Research Leipzig-Halle, Theodor-Lieser-Str. 4, 06120, Halle, Germany. [email protected]</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Auge</LastName><ForeName>Harald</ForeName><Initials>H</Initials></Author><Author ValidYN="Y"><LastName>Lafuma</LastName><ForeName>Lucile</ForeName><Initials>L</Initials></Author><Author ValidYN="Y"><LastName>Rogers</LastName><ForeName>William E</ForeName><Initials>WE</Initials></Author><Author ValidYN="Y"><LastName>Siemann</LastName><ForeName>Evan</ForeName><Initials>E</Initials></Author><Author ValidYN="Y"><LastName>Prati</LastName><ForeName>Daniel</ForeName><Initials>D</Initials></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D016428">Journal Article</PublicationType><PublicationType UI="D013485">Research Support, Non-U.S. Gov't</PublicationType><PublicationType UI="D013486">Research Support, U.S. Gov't, Non-P.H.S.</PublicationType><PublicationType UI="D016454">Review</PublicationType></PublicationTypeList><ArticleDate DateType="Electronic"><Year>2005</Year><Month>05</Month><Day>11</Day></ArticleDate></Article><MedlineJournalInfo><Country>Germany</Country><MedlineTA>Oecologia</MedlineTA><NlmUniqueID>0150372</NlmUniqueID><ISSNLinking>0029-8549</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000222" MajorTopicYN="Y">Adaptation, Physiological</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005075" MajorTopicYN="Y">Biological Evolution</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D017753" MajorTopicYN="Y">Ecosystem</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D014644" MajorTopicYN="Y">Genetic Variation</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008954" MajorTopicYN="Y">Models, Biological</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D010641" MajorTopicYN="Y">Phenotype</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D018521" MajorTopicYN="Y">Plant Physiological Phenomena</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D011157" MajorTopicYN="N">Population Dynamics</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D019655" MajorTopicYN="N">Quantitative Trait, Heritable</DescriptorName></MeshHeading></MeshHeadingList><NumberOfReferences>114</NumberOfReferences></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="received"><Year>2004</Year><Month>9</Month><Day>20</Day></PubMedPubDate><PubMedPubDate PubStatus="accepted"><Year>2005</Year><Month>2</Month><Day>22</Day></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2005</Year><Month>5</Month><Day>14</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2005</Year><Month>9</Month><Day>22</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="entrez"><Year>2005</Year><Month>5</Month><Day>14</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">15891837</ArticleId><ArticleId IdType="doi">10.1007/s00442-005-0070-z</ArticleId></ArticleIdList><ReferenceList><Reference><Citation>Am Nat. 2001 Feb;157(2):231-6</Citation><ArticleIdList><ArticleId IdType="pubmed">18707274</ArticleId></ArticleIdList></Reference><Reference><Citation>Heredity (Edinb). 1999 Oct;83(# (Pt 4)):476-84</Citation><ArticleIdList><ArticleId IdType="pubmed">10583550</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 1991 Sep;88(1):84-90</Citation><ArticleIdList><ArticleId IdType="pubmed">28312735</ArticleId></ArticleIdList></Reference><Reference><Citation>Nature. 2004 Feb 19;427(6976):731-3</Citation><ArticleIdList><ArticleId IdType="pubmed">14973484</ArticleId></ArticleIdList></Reference><Reference><Citation>Proc Biol Sci. 2003 Apr 22;270(1517):775-81</Citation><ArticleIdList><ArticleId IdType="pubmed">12737654</ArticleId></ArticleIdList></Reference><Reference><Citation>Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7043-50</Citation><ArticleIdList><ArticleId IdType="pubmed">10860969</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2000 Apr;9(4):443-55</Citation><ArticleIdList><ArticleId IdType="pubmed">10736047</ArticleId></ArticleIdList></Reference><Reference><Citation>Nature. 2002 May 2;417(6884):67-70</Citation><ArticleIdList><ArticleId IdType="pubmed">11986666</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2004 Aug;91(8):1155-62</Citation><ArticleIdList><ArticleId IdType="pubmed">21653471</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 2000 Oct 20;290(5491):521-3</Citation><ArticleIdList><ArticleId IdType="pubmed">11039934</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2004 Mar;138(4):521-31</Citation><ArticleIdList><ArticleId IdType="pubmed">14689299</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 2000 Mar 10;287(5459):1770-4</Citation><ArticleIdList><ArticleId IdType="pubmed">10710299</ArticleId></ArticleIdList></Reference><Reference><Citation>Trends Ecol Evol. 1993 Apr;8(4):133-7</Citation><ArticleIdList><ArticleId IdType="pubmed">21236129</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 1990 Apr 6;248(4951):88-9</Citation><ArticleIdList><ArticleId IdType="pubmed">17843323</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2000 May;9(5):541-56</Citation><ArticleIdList><ArticleId IdType="pubmed">10792698</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2005 May;14(6):1697-706</Citation><ArticleIdList><ArticleId IdType="pubmed">15836643</ArticleId></ArticleIdList></Reference><Reference><Citation>Proc Natl Acad Sci U S A. 2001 May 8;98(10):5446-51</Citation><ArticleIdList><ArticleId IdType="pubmed">11344292</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 1999 Sep;120(4):632-640</Citation><ArticleIdList><ArticleId IdType="pubmed">28308315</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2003 Jul;12(7):1747-56</Citation><ArticleIdList><ArticleId IdType="pubmed">12803628</ArticleId></ArticleIdList></Reference><Reference><Citation>Nature. 2003 Feb 6;421(6923):625-7</Citation><ArticleIdList><ArticleId IdType="pubmed">12571594</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 2003 Sep 5;301(5638):1377-80</Citation><ArticleIdList><ArticleId IdType="pubmed">12958360</ArticleId></ArticleIdList></Reference><Reference><Citation>Am Nat. 2002 Dec;160(6):705-11</Citation><ArticleIdList><ArticleId IdType="pubmed">18707459</ArticleId></ArticleIdList></Reference><Reference><Citation>Evolution. 1996 Aug;50(4):1512-1519</Citation><ArticleIdList><ArticleId IdType="pubmed">28565724</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 1997 Mar;110(1):99-108</Citation><ArticleIdList><ArticleId IdType="pubmed">28307474</ArticleId></ArticleIdList></Reference><Reference><Citation>Trends Ecol Evol. 1997 Jul;12(7):282-6</Citation><ArticleIdList><ArticleId IdType="pubmed">21238076</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2003 Oct;137(2):211-5</Citation><ArticleIdList><ArticleId IdType="pubmed">12883989</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2004 Jun;91(6):856-62</Citation><ArticleIdList><ArticleId IdType="pubmed">21653441</ArticleId></ArticleIdList></Reference><Reference><Citation>Genetica. 2001;112-113:183-98</Citation><ArticleIdList><ArticleId IdType="pubmed">11838765</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2003 May;135(3):451-7</Citation><ArticleIdList><ArticleId IdType="pubmed">12721836</ArticleId></ArticleIdList></Reference><Reference><Citation>Evolution. 2003 Apr;57(4):706-16</Citation><ArticleIdList><ArticleId IdType="pubmed">12778542</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2001 May;127(4):487-494</Citation><ArticleIdList><ArticleId IdType="pubmed">28547485</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2003 Jul;12(7):1689-702</Citation><ArticleIdList><ArticleId IdType="pubmed">12803624</ArticleId></ArticleIdList></Reference><Reference><Citation>Trends Ecol Evol. 1998 Aug 1;13(8):329-32</Citation><ArticleIdList><ArticleId IdType="pubmed">21238328</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2005 Jan;142(3):474-9</Citation><ArticleIdList><ArticleId IdType="pubmed">15655693</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2004 Feb;91(2):285-8</Citation><ArticleIdList><ArticleId IdType="pubmed">21653384</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2001 Dec;88(12):2243-51</Citation><ArticleIdList><ArticleId IdType="pubmed">21669657</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2001 Aug;88(8):1409-18</Citation><ArticleIdList><ArticleId IdType="pubmed">21669672</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 1999 Oct;8(10):1667-81</Citation><ArticleIdList><ArticleId IdType="pubmed">10583830</ArticleId></ArticleIdList></Reference></ReferenceList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">15891779</PMID><DateCompleted><Year>2005</Year><Month>07</Month><Day>27</Day></DateCompleted><DateRevised><Year>2022</Year><Month>03</Month><Day>09</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">0888-8051</ISSN><JournalIssue CitedMedium="Print"><Issue>513</Issue><PubDate><Year>2005</Year><Month>Jan</Month></PubDate></JournalIssue><Title>National Toxicology Program technical report series</Title><ISOAbbreviation>Natl Toxicol Program Tech Rep Ser</ISOAbbreviation></Journal>NTP toxicology and carcinogenesis studies of decalin (CAS No. 91-17-8) in F344/N rats and B6C3F(1) mice and a toxicology study of decalin in male NBR rats (inhalation studies).
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Plant invasions often involve rapid evolutionary change. Founder effects, hybridization, and adaptation to novel environments cause genetic differentiation between native and introduced populations and may contribute to the success of invaders. An influential idea in this context has been the Evolution of Increased Competitive Ability (EICA) hypothesis. It proposes that after enemy release plants rapidly evolve to be less defended but more competitive, thereby increasing plant vigour in introduced populations. To detect evolutionary change in invaders, comparative studies of native versus introduced populations are needed. Here, we review the current empirical evidence from: (1) comparisons of phenotypic variation in natural populations; (2) comparisons of molecular variation with neutral genetic markers; (3) comparisons of quantitative genetic variation in a common environment; and (4) comparisons of phenotypic plasticity across different environments. Field data suggest that increased vigour and reduced herbivory are common in introduced plant populations. In molecular studies, the genetic diversity of introduced populations was not consistently different from that of native populations. Multiple introductions of invasive plants appear to be the rule rather than the exception. In tests of the EICA hypothesis in a common environment, several found increased growth or decreased resistance in introduced populations. However, few provided a full test of the EICA hypothesis by addressing growth and defence in the same species. Overall, there is reasonable empirical evidence to suggest that genetic differentiation through rapid evolutionary change is important in plant invasions. We discuss conceptual and methodological issues associated with cross-continental comparisons and make recommendations for future research. When testing for EICA, greater emphasis should be put on competitive ability and plant tolerance. Moreover, it is important to address evolutionary change in characteristics other than defence and growth that could play a role in plant invasions.</Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Bossdorf</LastName><ForeName>Oliver</ForeName><Initials>O</Initials><AffiliationInfo><Affiliation>Department of Community Ecology, UFZ-Centre for Environmental Research Leipzig-Halle, Theodor-Lieser-Str. 4, 06120, Halle, Germany. [email protected]</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Auge</LastName><ForeName>Harald</ForeName><Initials>H</Initials></Author><Author ValidYN="Y"><LastName>Lafuma</LastName><ForeName>Lucile</ForeName><Initials>L</Initials></Author><Author ValidYN="Y"><LastName>Rogers</LastName><ForeName>William E</ForeName><Initials>WE</Initials></Author><Author ValidYN="Y"><LastName>Siemann</LastName><ForeName>Evan</ForeName><Initials>E</Initials></Author><Author ValidYN="Y"><LastName>Prati</LastName><ForeName>Daniel</ForeName><Initials>D</Initials></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D016428">Journal Article</PublicationType><PublicationType UI="D013485">Research Support, Non-U.S. Gov't</PublicationType><PublicationType UI="D013486">Research Support, U.S. Gov't, Non-P.H.S.</PublicationType><PublicationType UI="D016454">Review</PublicationType></PublicationTypeList><ArticleDate DateType="Electronic"><Year>2005</Year><Month>05</Month><Day>11</Day></ArticleDate></Article><MedlineJournalInfo><Country>Germany</Country><MedlineTA>Oecologia</MedlineTA><NlmUniqueID>0150372</NlmUniqueID><ISSNLinking>0029-8549</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000222" MajorTopicYN="Y">Adaptation, Physiological</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005075" MajorTopicYN="Y">Biological Evolution</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D017753" MajorTopicYN="Y">Ecosystem</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D014644" MajorTopicYN="Y">Genetic Variation</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008954" MajorTopicYN="Y">Models, Biological</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D010641" MajorTopicYN="Y">Phenotype</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D018521" MajorTopicYN="Y">Plant Physiological Phenomena</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D011157" MajorTopicYN="N">Population Dynamics</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D019655" MajorTopicYN="N">Quantitative Trait, Heritable</DescriptorName></MeshHeading></MeshHeadingList><NumberOfReferences>114</NumberOfReferences></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="received"><Year>2004</Year><Month>9</Month><Day>20</Day></PubMedPubDate><PubMedPubDate PubStatus="accepted"><Year>2005</Year><Month>2</Month><Day>22</Day></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2005</Year><Month>5</Month><Day>14</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2005</Year><Month>9</Month><Day>22</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="entrez"><Year>2005</Year><Month>5</Month><Day>14</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">15891837</ArticleId><ArticleId IdType="doi">10.1007/s00442-005-0070-z</ArticleId></ArticleIdList><ReferenceList><Reference><Citation>Am Nat. 2001 Feb;157(2):231-6</Citation><ArticleIdList><ArticleId IdType="pubmed">18707274</ArticleId></ArticleIdList></Reference><Reference><Citation>Heredity (Edinb). 1999 Oct;83(# (Pt 4)):476-84</Citation><ArticleIdList><ArticleId IdType="pubmed">10583550</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 1991 Sep;88(1):84-90</Citation><ArticleIdList><ArticleId IdType="pubmed">28312735</ArticleId></ArticleIdList></Reference><Reference><Citation>Nature. 2004 Feb 19;427(6976):731-3</Citation><ArticleIdList><ArticleId IdType="pubmed">14973484</ArticleId></ArticleIdList></Reference><Reference><Citation>Proc Biol Sci. 2003 Apr 22;270(1517):775-81</Citation><ArticleIdList><ArticleId IdType="pubmed">12737654</ArticleId></ArticleIdList></Reference><Reference><Citation>Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7043-50</Citation><ArticleIdList><ArticleId IdType="pubmed">10860969</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2000 Apr;9(4):443-55</Citation><ArticleIdList><ArticleId IdType="pubmed">10736047</ArticleId></ArticleIdList></Reference><Reference><Citation>Nature. 2002 May 2;417(6884):67-70</Citation><ArticleIdList><ArticleId IdType="pubmed">11986666</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2004 Aug;91(8):1155-62</Citation><ArticleIdList><ArticleId IdType="pubmed">21653471</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 2000 Oct 20;290(5491):521-3</Citation><ArticleIdList><ArticleId IdType="pubmed">11039934</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2004 Mar;138(4):521-31</Citation><ArticleIdList><ArticleId IdType="pubmed">14689299</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 2000 Mar 10;287(5459):1770-4</Citation><ArticleIdList><ArticleId IdType="pubmed">10710299</ArticleId></ArticleIdList></Reference><Reference><Citation>Trends Ecol Evol. 1993 Apr;8(4):133-7</Citation><ArticleIdList><ArticleId IdType="pubmed">21236129</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 1990 Apr 6;248(4951):88-9</Citation><ArticleIdList><ArticleId IdType="pubmed">17843323</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2000 May;9(5):541-56</Citation><ArticleIdList><ArticleId IdType="pubmed">10792698</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2005 May;14(6):1697-706</Citation><ArticleIdList><ArticleId IdType="pubmed">15836643</ArticleId></ArticleIdList></Reference><Reference><Citation>Proc Natl Acad Sci U S A. 2001 May 8;98(10):5446-51</Citation><ArticleIdList><ArticleId IdType="pubmed">11344292</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 1999 Sep;120(4):632-640</Citation><ArticleIdList><ArticleId IdType="pubmed">28308315</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2003 Jul;12(7):1747-56</Citation><ArticleIdList><ArticleId IdType="pubmed">12803628</ArticleId></ArticleIdList></Reference><Reference><Citation>Nature. 2003 Feb 6;421(6923):625-7</Citation><ArticleIdList><ArticleId IdType="pubmed">12571594</ArticleId></ArticleIdList></Reference><Reference><Citation>Science. 2003 Sep 5;301(5638):1377-80</Citation><ArticleIdList><ArticleId IdType="pubmed">12958360</ArticleId></ArticleIdList></Reference><Reference><Citation>Am Nat. 2002 Dec;160(6):705-11</Citation><ArticleIdList><ArticleId IdType="pubmed">18707459</ArticleId></ArticleIdList></Reference><Reference><Citation>Evolution. 1996 Aug;50(4):1512-1519</Citation><ArticleIdList><ArticleId IdType="pubmed">28565724</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 1997 Mar;110(1):99-108</Citation><ArticleIdList><ArticleId IdType="pubmed">28307474</ArticleId></ArticleIdList></Reference><Reference><Citation>Trends Ecol Evol. 1997 Jul;12(7):282-6</Citation><ArticleIdList><ArticleId IdType="pubmed">21238076</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2003 Oct;137(2):211-5</Citation><ArticleIdList><ArticleId IdType="pubmed">12883989</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2004 Jun;91(6):856-62</Citation><ArticleIdList><ArticleId IdType="pubmed">21653441</ArticleId></ArticleIdList></Reference><Reference><Citation>Genetica. 2001;112-113:183-98</Citation><ArticleIdList><ArticleId IdType="pubmed">11838765</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2003 May;135(3):451-7</Citation><ArticleIdList><ArticleId IdType="pubmed">12721836</ArticleId></ArticleIdList></Reference><Reference><Citation>Evolution. 2003 Apr;57(4):706-16</Citation><ArticleIdList><ArticleId IdType="pubmed">12778542</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2001 May;127(4):487-494</Citation><ArticleIdList><ArticleId IdType="pubmed">28547485</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 2003 Jul;12(7):1689-702</Citation><ArticleIdList><ArticleId IdType="pubmed">12803624</ArticleId></ArticleIdList></Reference><Reference><Citation>Trends Ecol Evol. 1998 Aug 1;13(8):329-32</Citation><ArticleIdList><ArticleId IdType="pubmed">21238328</ArticleId></ArticleIdList></Reference><Reference><Citation>Oecologia. 2005 Jan;142(3):474-9</Citation><ArticleIdList><ArticleId IdType="pubmed">15655693</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2004 Feb;91(2):285-8</Citation><ArticleIdList><ArticleId IdType="pubmed">21653384</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2001 Dec;88(12):2243-51</Citation><ArticleIdList><ArticleId IdType="pubmed">21669657</ArticleId></ArticleIdList></Reference><Reference><Citation>Am J Bot. 2001 Aug;88(8):1409-18</Citation><ArticleIdList><ArticleId IdType="pubmed">21669672</ArticleId></ArticleIdList></Reference><Reference><Citation>Mol Ecol. 1999 Oct;8(10):1667-81</Citation><ArticleIdList><ArticleId IdType="pubmed">10583830</ArticleId></ArticleIdList></Reference></ReferenceList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">15891779</PMID><DateCompleted><Year>2005</Year><Month>07</Month><Day>27</Day></DateCompleted><DateRevised><Year>2022</Year><Month>03</Month><Day>09</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">0888-8051</ISSN><JournalIssue CitedMedium="Print"><Issue>513</Issue><PubDate><Year>2005</Year><Month>Jan</Month></PubDate></JournalIssue><Title>National Toxicology Program technical report series</Title><ISOAbbreviation>Natl Toxicol Program Tech Rep Ser</ISOAbbreviation></Journal><ArticleTitle>NTP toxicology and carcinogenesis studies of decalin (CAS No. 91-17-8) in F344/N rats and B6C3F(1) mice and a toxicology study of decalin in male NBR rats (inhalation studies).</ArticleTitle><Pagination><StartPage>1</StartPage><EndPage>316</EndPage><MedlinePgn>1-316</MedlinePgn></Pagination><Abstract><AbstractText Label="UNLABELLED">Decalin is used as an industrial solvent for naphthalene, fats, resins, oils, and waxes. It is also used as a substitute for turpentine in lacquers, paints, and varnishes; as a solvent and stabilizer for shoe polishes and floor waxes; and as a constituent of motor fuels and lubricants. Other applications include use as a paint thinner and remover, a patent fuel in stoves, a high-density fuel in submarine-launched cruise missile systems, and in stain removal and cleaning machinery. Decalin was nominated for study by the National Cancer Institute because of its chemical structure, its potential for consumer exposure, and a lack of adequate testing of the chemical. Male and female F344/N rats and B6C3F(1) mice were exposed to decalin (greater than 99% pure) by inhalation for 2 weeks, 3 months, or 2 years. Groups of male NBR rats were exposed to decalin for 2 weeks. Male NBR rats do not produce alpha2u-globulin; the NBR rats were included to study the relationship of alpha2u-globulin and renal lesion induction. Genetic toxicology studies were conducted in Salmonella typhimurium and mouse peripheral blood erythrocytes. 2-WEEK STUDIES IN RATS: Groups of five male and five female F344/N rats and five male NBR rats were exposed to 0, 25, 50, 100, 200, or 400 ppm decalin vapor 6 hours per day, 5 days per week for 16 days. All rats survived to the end of the study, and mean body weights of exposed groups were similar to those of the chamber controls. Renal toxicity studies were performed in male F344/N and NBR rats. The numbers of labeled cells and the labeling indices in the left kidney of 200 and 400 ppm F344/N male rats were significantly greater than those in the chamber controls. The alpha2u-globulin/soluble protein ratios were significantly increased in all exposed groups of F344/N rats. Liver weights of male F344/N and NBR rats exposed to 100 ppm or greater were significantly increased, as were those of all exposed groups of females. Kidney weights of male F344/N rats exposed to 50 ppm or greater were significantly increased. Exposure-related hyaline droplet accumulation, degeneration and regeneration of renal cortical tubules, and granular casts occurred in the kidney of exposed F344/N male rats. 2-WEEK STUDIES IN MICE: Groups of five male and five female B6C3F(1) mice were exposed to 0, 25, 50, 100, 200, or 400 ppm decalin vapor 6 hours per day, 5 days per week for 17 days. All mice survived to the end of the study, and mean body weights of exposed groups were similar to those of the chamber control groups. Liver weights of 200 and 400 ppm males and females and 100 ppm females were significantly increased. 3-MONTH STUDY IN RATS: Groups of 25 male and 20 female F344/N rats were exposed to 0, 25, 50, 100, 200, or 400 ppm decalin vapor 6 hours per day, 5 days per week for 2 (five male renal toxicity rats), 6 (10 male and 10 female clinical pathology rats), or 14 (10 core study rats) weeks. All rats survived to the end of the study, and mean body weights of exposed groups were similar to those of the chamber control groups. Urinalysis results indicated that decalin exposure caused increases in urine glucose and protein concentrations and enzyme activities that were consistent with the renal lesions observed microscopically. Renal toxicity studies were performed on rats sacrificed at 2 and 6 weeks and at the end of the study. In kidney tissue examined for cell proliferation, the numbers of PCNA-labeled cells and labeling indices were generally significantly greater than those of the chamber controls in exposed groups of rats at all three time points. Concentrations of alpha2u-globulin in the kidney as well as the alpha2u-globulin/soluble protein ratios were significantly increased at week 2 in all exposed groups and in the 200 and 400 ppm groups at week 6 and at the end of the study. Absolute and/or relative kidney and liver weights of male rats exposed to 50 ppm or greater were increased. Incidences of renal tubule regeneration and granular casts in the medulla of the kidney in exposed male rats were increased, and the severities of hyaline droplets generally increased with increasing exposure concentration. 3-MONTH STUDY IN MICE: Groups of 10 male and 10 female B6C3F(1) mice were exposed to 0, 25, 50, 100, 200, or 400 ppm decalin vapor 6 hours per day, 5 days per week for 14 weeks. All mice survived to the end of the study, and mean body weights of exposed groups were similar to those of the chamber control groups. Liver weights of 200 and 400 ppm males and females were significantly increased. There was a significant exposure concentration-related decrease in the absolute spermatid head count and a significant decrease in absolute head count of the 400 ppm group compared to the chamber controls. Incidences of centrilobular cytomegaly of the liver were increased in exposed male mice. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female F344/N rats were exposed to 0, 25, 50 (male rats only), 100, or 400 ppm (female rats only) decalin vapor 6 hours per day, 5 days per week for 105 weeks. A group of 20 male rats was exposed to 400 ppm. Survival of exposed groups was similar to that of the chamber control groups. Mean body weights of 400 ppm males were slightly less than those of the chamber controls during the second year of the study. Incidences of renal tubule adenoma and adenoma or carcinoma (combined) and of benign or malignant pheochromocytoma (combined) of the adrenal medulla in 100 and 400 ppm males were significantly increased. There was a significant association between nephropathy severity and adrenal pheochromocytoma incidence. Nonneoplastic lesions related to decalin exposure occurred in the kidney of male rats. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female B6C3F(1) mice were exposed to 0, 25, 100, or 400 ppm decalin vapor 6 hours per day, 5 days per week for 105 weeks. Survival of exposed mice was similar to that of the chamber controls. Mean body weights of exposed groups were generally similar to those of the chamber control groups throughout the study. Increased incidences of hepatocellular neoplasms occurred in 25 and 400 ppm female mice, and the incidences of centrilobular hypertrophy, necrosis, syncytial alteration, and erythrophagocytosis of the liver in 400 ppm males were significantly increased. The incidences of uterine stromal polyp and stromal polyp or stromal sarcoma (combined) occurred with positive trends in female mice.<AbstractText Label="PHARMACOKINETIC MODEL" NlmCategory="UNASSIGNED">The rate of metabolism of decalin was the same for males and females in rats and mice. Also in rats and mice, decalin metabolism was saturated at less than 400 ppm. Increased labeling indices in male rats were likely due to changes related to alpha2u-globulin.<AbstractText Label="GENETIC TOXICOLOGY" NlmCategory="RESULTS">Decalin was not mutagenic in S. typhimurium strains TA97, TA98, TA100, or TA1535, with or without induced hamster or rat liver S9 enzymes. A small but significant increase in the frequency of micronucleated normochromatic erythrocytes was noted in male mice exposed to decalin for 3 months; however, no induction of micronuclei was observed in female mice.<AbstractText Label="CONCLUSIONS" NlmCategory="CONCLUSIONS">Under the conditions of these studies, there was clear evidence of carcinogenic activity of decalin in male F344/N rats based on increased incidences of renal tubule neoplasms. The increased incidences of benign or malignant pheochromocytoma (combined) of the adrenal medulla in male rats were also considered to be exposure related. There was no evidence of carcinogenic activity of decalin in female F344/N rats exposed to 25, 100, or 400 ppm. There was no evidence of carcinogenic activity of decalin in male B6C3F(1) mice exposed to 25, 100, or 400 ppm. There was equivocal evidence of carcinogenic activity of decalin in female B6C3F(1) mice based on marginally increased incidences of hepatocellular and uterine neoplasms. Exposure of male rats to decalin resulted in nonneoplastic lesions of the kidney characteristic of alpha2u-globulin accumulation. Nonneoplastic lesions of the liver were observed in male mice exposed to decalin.
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2,337,581 |
Prion biology relevant to bovine spongiform encephalopathy.
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Bovine spongiform encephalopathy (BSE) and chronic wasting disease (CWD) of deer and elk are a threat to agriculture and natural resources, as well as a human health concern. Both diseases are transmissible spongiform encephalopathies (TSE), or prion diseases, caused by autocatalytic conversion of endogenously encoded prion protein (PrP) to an abnormal, neurotoxic conformation designated PrPsc. Most mammalian species are susceptible to TSE, which, despite a range of species-linked names, is caused by a single highly conserved protein, with no apparent normal function. In the simplest sense, TSE transmission can occur because PrPsc is resistant to both endogenous and environmental proteinases, although many details remain unclear. Questions about the transmission of TSE are central to practical issues such as livestock testing, access to international livestock markets, and wildlife management strategies, as well as intangible issues such as consumer confidence in the safety of the meat supply. The majority of BSE cases seem to have been transmitted by feed containing meat and bone meal from infected animals. In the United Kingdom, there was a dramatic decrease in BSE cases after neural tissue and, later, all ruminant tissues were banned from ruminant feed. However, probably because of heightened awareness and widespread testing, there is growing evidence that new variants of BSE are arising "spontaneously," suggesting ongoing surveillance will continue to find infected animals. Interspecies transmission is inefficient and depends on exposure, sequence homology, TSE donor strain, genetic polymorphism of the host, and architecture of the visceral nerves if exposure is by an oral route. Considering the low probability of interspecies transmission, the low efficiency of oral transmission, and the low prion levels in nonnervous tissues, consumption of conventional animal products represents minimal risk. However, detection of rare events is challenging, and TSE literature is characterized by subsequently unsupported claims of species barriers or absolute tissue safety. This review presents an overview of TSE and summarizes recent research on pathogenesis and transmission.
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2,337,582 |
An N-ethyl-N-nitrosourea screen for genes involved in variegation in the mouse.
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We have developed a sensitized screen to identify genes involved in gene silencing, using random N-ethyl-N-nitrosourea mutagenesis on mice carrying a variegating GFP transgene. The dominant screen has produced six mutant lines, including both suppressors and enhancers of variegation. All are semidominant and five of the six are homozygous embryonic lethal. In one case, the homozygous lethality depends on sex: homozygous females die at midgestation and display abnormal DNA methylation of the X chromosome, whereas homozygous males are viable. Linkage analysis reveals that the mutations map to unique chromosomal locations. We have studied the effect of five of the mutations on expression of an endogenous allele known to be sensitive to epigenetic state, agouti viable yellow. In all cases, there is an effect on penetrance, and in most cases, parent of origin and sex-specific effects are detected. This screen has identified genes that are involved in epigenetic reprogramming of the genome, and the behavior of the mutant lines suggests a common mechanism between X inactivation and transgene and retrotransposon silencing. Our findings raise the possibility that the presence or absence of the X chromosome in mammals affects the establishment of the epigenetic state at autosomal loci by acting as a sink for proteins involved in gene silencing. The study demonstrates the power of sensitized screens in the mouse not only for the discovery of novel genes involved in a particular process but also for the elucidation of the biology of that process.
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2,337,583 |
Detection of CFTR mutations using ARMS and low-density microarrays.
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The amplification refractory mutation system (ARMS) is routinely used for the identification of specific mutations within genomes. This PCR-based assay, although simple, is performed at a low-throughput scale, usually requiring gel-electrophoresis for the identification of specific mutations. We have applied the ARMS technology to a low-density microarray system to facilitate the needs of the medical clinic; high-throughput capabilities and ease-of-use. Mutations within the cystic fibrosis transmembrane regulator (CFTR) gene (DeltaF508, 1717-1G>A, G542X, 621+1G>T, and N1303K) were detected by multiplex-ARMS-PCR, and fragments were post-PCR labeled with Cy5. Amine-modified probes specific for both the wild-type and mutant forms of each mutation site were attached to glass substrates. Following hybridization of the PCR fragments to the attached probes (in a low-density microarray format), confirmation of the presence of specific sequences was achieved using a commercial scanner, as well as a fabricated low-cost fluorescent detector and applicable software. The novel combination of the ARMS and low-density microarray technologies allows for a high-throughput, simple means to rapidly identify multiple known mutations for many genetic diseases including cystic fibrosis.
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2,337,584 |
Living with a hereditary disease: persons with muscular dystrophy and their next of kin.
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This qualitative study describes conceptions and experiences of the hereditary aspect of muscular dystrophy (MD) from both the patients' and the next of kin's perspective. Different diagnoses of MD are included: dystrophia myotonica, myopathia distalis tarda hereditaria, Becker MD, facioscapulohumeral MD, limb-girdle MD, Emery-Dreifuss and undetermined proximal MD (Duchenne MD is not included). Interviews were conducted with 46 persons with MD and 36 next of kin. The interviews were subjected to inductive content analysis. Only two in each group did not spontaneously mention anything related to the fact that MD is disease with dominant or recessive inheritance. It was found that heredity has a prominent place in the thoughts and feelings of the family. These thoughts were classified as Becoming aware of MD and its hereditary nature, looking into the pedigree, acquiring an understanding of MD, thoughts about genetic testing, interpreting the risk, whether to have children or not, feelings related to the future, and feelings of responsibility and guilt. Families with MD need medical information and the opportunity for genetic testing as well as support and counseling in coming to terms with living with a hereditary disease, whether or not that includes a decision to take a test.
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2,337,585 |
Development and modification of child food preferences and eating patterns: behavior genetics strategies.
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Behavioral genetics (BG) designs can offer useful strategies for studying the development of child food preferences and eating patterns. This review summarizes BG designs that tested familial influences on child eating behavior and implicated both genetic and home environmental factors. A range of BG strategies, including family and pseudo-family designs, classic twins designs, discordant sibling designs, cotwin control designs, and high-risk designs, have provided information on child development that could not have been obtained from the analysis of singletons. BG designs can provide can powerful tools for testing environmental theories of child nutrition and, potentially, for better understanding between-child variability in response to dietary interventions for overweight. The term BG may misleadingly imply only the classic twin design or just heritability estimation; BG strategies can be adapted creatively to address a range of questions concerning the development of child appetite and eating regulation.
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2,337,586 |
Allele variations in the OCA2 gene (pink-eyed-dilution locus) are associated with genetic susceptibility to melanoma.
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The occuloalbinism 2 (OCA2) gene, localized at 15q11, encodes a melanosomal transmembrane protein that is involved in the most common form of human occulo-cutaneous albinism, a human genetic disorder characterized by fair pigmentation and susceptibility to skin cancer. We wondered whether allele variations at this locus could influence susceptibility to malignant melanoma (MM). In all, 10 intragenic single-nucleotide polymorphisms (SNPs) were genotyped in 113 patients with melanomas and in 105 Caucasian control subjects with no personal or family history of skin cancer. By comparing allelic distribution between cases and controls, we show that MM and OCA2 are associated (p value=0.030 after correction for multiple testing). Then, a recently developed strategy, the 'combination test' enabled us to show that a combination formed by two SNPs was most strongly associated to MM, suggesting a possible interaction between intragenic SNPs. In addition, the role of OCA2 on MM risk was also detected using a logistic model taking into account the presence of variants of the melanocortin 1 receptor gene (MC1R, a key pigmentation gene) and all pigmentation characteristics as melanoma risk factors. Our data demonstrate that a second pigmentation gene, in addition to MC1R, is involved in genetic susceptibility to melanoma.
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2,337,587 |
ATP8B1 mutations in British cases with intrahepatic cholestasis of pregnancy.
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Intrahepatic cholestasis of pregnancy (ICP) affects approximately 0.7% of pregnancies in the UK and is associated with prematurity, fetal distress, and intrauterine death. Homozygous mutations in the ATP8B1 gene cause cholestasis with a normal serum gamma-glutamyl transpeptidase (gamma-GT), and have been reported in two forms of cholestasis: progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis (BRIC).</AbstractText>To establish whether mutations in ATP8B1 are associated with ICP in British cases</AbstractText>Sixteen well phenotyped women with ICP without raised gamma-GT were selected for sequence analysis. Subsequently, 182 patients and 120 controls were examined for the presence of the variants detected.</AbstractText>All coding exons were sequenced in 16 cases. Eight ICP cases, including two women carrying a mutation, were investigated using in vivo hepatic (31)P magnetic resonance spectroscopy (MRS) RESULTS: Two heterozygous ATP8B1 transitions (208G>A and 2599C>T) that resulted in amino acid substitutions were identified; 208G>A was identified in three cases. MRS revealed an increased phosphodiester signal (Mann-Whitney U test, p = 0.03) and a decreased phosphomonoester/phosphodiester ratio (p = 0.04) in ICP cases compared with controls.</AbstractText>We were able to demonstrate ATP8B1 mutations in ICP. MRS studies suggest that susceptibility to ICP is associated with a relative rise in biliary phospholipid. These data also suggest that MRS may be used for non-invasive assessment of the liver and biliary constituents in cholestasis.</AbstractText>
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2,337,588 |
Retinoblastoma: genetic testing versus conventional clinical screening in India.
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Genetic testing is increasingly being used to evaluate susceptibility to hereditary diseases because it is a cost effective screening method. Predictive testing for retinoblastoma can help to save the vision and avoid unnecessary (and invasive) eye examinations for probands and their close relatives. This study was undertaken to evaluate the cost effectiveness of the retinoblastoma genetic screening strategy established in our hospital.</AbstractText>Cytogenetic study of peripheral blood, mutational, and methylation analyses from the tumor DNA of 25 patients with retinoblastoma was undertaken. The cost for retinoblastoma (RB1) gene screening was calculated based on the cost of the chemicals and consumables used and the clinical examination charges at our hospital. A comparison was made between the cost of genetic screening and clinical testing for retinoblastoma. Retinoblastoma patients underwent clinical management and genetic testing at Sankara Nethralaya, Chennai, India.</AbstractText>By adopting a genetic screening strategy, a 3.5-fold cost saving was seen for a proband while a 6-fold saving was seen for a family with two sibs compared to the cost of clinical examination. The clinical examination fee and cost of genetic screening for a proband was dollarUS536 and dollarUS152, respectively, while for a nuclear family with two sibs the costs were dollarUS1071 and dollarUS175, respectively.</AbstractText>Savings for a family will be higher if indirect costs, such as savings in travel times to and from the hospital and labor savings, were taken into account. Cost will be a major factor in determining the implementation of genetic screening for RB1 gene in the clinical practice.</AbstractText>In our study in India, genetic screening for retinoblastoma was cheaper than conventional screening and was useful in the genetic counseling of the families.</AbstractText>
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2,337,589 |
Genetic testing in the myelodysplastic syndromes: molecular insights into hematologic diversity.
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The myelodysplastic syndromes (MDS) are associated with a diverse set of acquired somatic genetic abnormalities. Bone marrow karyotyping provides important diagnostic and prognostic information and should be attempted in all patients who are suspected of having MDS. Fluorescent in situ hybridization (FISH) studies on blood or marrow may also be valuable in selected cases, such as patients who may have 5q- syndrome or those who have undergone hematopoletic stem cell transplantation. The MDS-associated cytogenetic abnormalities that have been defined by karyotyping and FISH studies have already contributed substantially to our current understanding of the biology of malignant myeloid disorders, but the pathobiological meaning of common, recurrent chromosomal lesions such as del(5q), del(20q), and monosomy 7 is still unknown. The great diversity of the cytogenetic findings described in MDS highlights the molecular heterogeneity of this cluster of diseases. We review the common and pathophysiologically interesting genetic abnormalities associated with MDS, focusing on the clinical utility of conventional cytogenetic assays and selected FISH studies. In addition, we discuss a series of well-defined MDS-associated point mutations and outline the potential for further insights from newer techniques such as global gene expression profiling and array-based comparative genomic hybridization.
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2,337,590 |
Polymorphisms in DNA repair genes as risk factors for spina bifida and orofacial clefts.
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Repairing DNA damage is critical during embryogenesis because development involves sensitive periods of cell proliferation, and abnormal cell growth or death can result in malformations. Knockout mouse experiments have demonstrated that disruption of DNA repair genes results in embryolethality and structural defects. Studies using mid-organogenesis rat embryos showed that DNA repair genes were variably expressed. It is hypothesized that polymorphisms that alter the functionality of DNA repair enzymes may modify the risk of malformations. We conducted a case-control analysis to investigate the relationship between DNA repair gene polymorphisms and the risk of spina bifida and oral clefts. Newborn screening blood spot DNA was obtained for 250 cases (125 spina bifida, 125 oral clefts) identified by the California Birth Defects Monitoring Program, and 350 non-malformation controls identified from birth records. Six single nucleotide polymorphisms of five DNA repair genes representing three distinct repair pathways were interrogated including: XRCC1 (Arg399Gln), APE1 (Asp148Glu), XRCC3 (Thr241Met), hOGG1(Ser326Cys), XPD (Asp312Asn, Lys751Gln). Elevated or decreased odds ratios (OR, adjusted for race/ethnicity) for spina bifida were found for genotypes containing at least one copy of the variant allele for XPD [751Gln, OR = 1.62; 95% confidence interval (CI) = 1.05-2.50] and APE 148 (OR = 0.58; CI = 0.37-0.90). A decreased risk of oral clefts was found for XRCC3 (OR = 0.62; CI = 0.39-0.99) and hOGG1 (326 Cys/Cys, OR = 0.22; CI = 0.06-0.78). This study suggested that polymorphisms of DNA repair genes, representing different major repair pathways, may affect risk of two major birth defects. Future, larger studies, examining additional repair genes, birth defects, and interaction with exposures are recommended.
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2,337,591 |
Autosomal recessive omodysplasia: early prenatal diagnosis and a possible clue to the gene location.
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Autosomal recessive omodysplasia (ARO), a rare congenital skeletal dysplasia, is characterized by micromelia and craniofacial anomalies. Upper and lower limbs are affected in contrast to the dominant form in which the lower limbs are normal. Radiographic features include shortening and distal tapering of the humerus and femur, proximal radioulnar diastasis, and anterolateral radial head dislocation. We present a recurrence of ARO in a family, detected on prenatal ultrasound at 13 weeks of gestation. Chromosome analysis of the products of conception and the affected sibling showed a paternally-inherited paracentric inversion of 15q13 to q21.3. Due to similarities in the clinical phenotype between diastrophic dysplasia and this condition, testing for DTDST mutation was performed with no mutation detected.
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2,337,592 |
Are the betaine-homocysteine methyltransferase (BHMT and BHMT2) genes risk factors for spina bifida and orofacial clefts?
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Abnormalities in folate and/or homocysteine metabolism may adversely influence embryonic development, leading to the birth of infants with a variety of congenital malformations, including neural tube defects (NTDs) and craniofacial abnormalities. Based upon suggestive evidence that periconceptional folic acid supplementation is effective in preventing a significant proportion of the aforementioned birth defects, genetic variation in the folate biosynthetic pathways may influence the infant's susceptibility to these birth defects. The goal of our study was to investigate sequence variations in the betaine-homocysteine methyltransferase (BHMT) and betaine-homocysteine methyltransferase (BHMT2) genes as modifiers of risk of spina bifida, cleft palate, and cleft lip and palate. The results of this study indicated that individuals homozygous for the single nucleotide polymorphism R239Q in BHMT did not have elevated risks for spina bifida. Genotype frequencies for the BHMT2 rs626105 polymorphism also did not reveal any elevated risks for spina bifida, and only a modest, imprecise elevation of risk for orofacial clefts. The results of these experiments suggest that variants of the BHMT/BHMT2 genes in infants do not substantially contribute to the risk of spina bifida or orofacial clefts in our study population.
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2,337,593 |
Contribution of BRCA1 and BRCA2 germ-line mutations to the incidence of breast cancer in young women: results from a prospective population-based study in France.
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The prevalence of BRCA1/2 germ-line mutations was assessed in a prospective population-based series of early-onset breast cancer (BC) patients in France, and the usefulness of a clinical assessment of hereditary BC risk, based on multiple criteria including pedigree structure, was evaluated. Through the Rhone region BC registry, 232 women diagnosed with BC before 46 years of age were included. They were tested for BRCA1/2 mutations an average of 10 months after diagnosis. All the women were classified according to their family history of cancer: high risk of hereditary breast cancer (HBC), low risk of HBC, isolated BC, and unknown HBC risk. Deleterious mutations were observed in 21 women (9.1%): 15 (6.5%) BRCA1 and 6 (2.6%) BRCA2. Mutations were more prevalent in women who developed BC before age 41 than in women who developed BC between ages 41 and 45 (12.8% versus 5.2%, respectively, P = 0.04). A high prevalence of BRCA1/2 mutations was found among women in the high-risk category with particular family features (i.e., small family size, predominantly male pedigree, specific cancers; 23.5%) and among women with isolated BC before age 41 and with five or fewer close adult female relatives (16.6%). According to the 10% probability level recommended by the American Society of Clinical Oncology guidelines for genetic testing of cancer, BRCA1/2 mutation screening should be considered for all women diagnosed before age 41, except for those with isolated BC in a large pedigree including multiple unaffected female relatives. The clinical assessment of HBC risk that we have developed should help in the decision to perform genetic testing.
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2,337,594 |
Genetic testing for inherited colon cancer.
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The genes associated with each of the inherited syndromes of colon cancer have now been identified, and genetic testing is available for diagnosis. These syndromes include familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer, Peutz-Jeghers syndrome, juvenile polyposis syndrome, and, possibly, Cowden's syndrome. Clinical genetic testing approaches have been developed for each of these syndromes and are now a part of accepted clinical care. Disease-causing mutations can be found in the majority of families affected with one of the inherited syndromes, and, most importantly, once a mutation is found in an index case of the family, relatives can be tested for the presence or absence of that mutation with near 100% accuracy. Cancer screening and management in syndrome families is then based on the results of genetic testing. For the physician to order and properly interpret genetic tests, a basic understanding of the types of mutations that lead to inherited disease and the methods for detecting them is vital. These issues will be presented. Additional clinical issues somewhat unique to genetic testing include genetic counseling and informed consent for genetic testing, both of which will also be reviewed. Often the most difficult aspect of genetic testing is deciding which patients and families should undergo the testing. Furthermore, this issue is quite specific for each of the syndromes. Thus, following presentation of general principles of selection for genetic testing, a detailed approach for identifying persons who should undergo testing for each of the individual syndromes will be given, together with relevant descriptions of the syndromes. Finally, the ongoing work to discover new and possibly more common but less penetrant colon cancer susceptibility genes that cause common familial colon cancer will be presented.
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2,337,595 |
The (CA)n polymorphism of the TNFR2 gene is associated with peak bone density in Chinese nuclear families.
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Low peak bone density (PBD) in adulthood is an important determinant of osteoporotic fracture (OF) in the elderly. The tumor necrosis factor receptor 2 (TNFR2) gene has been considered as an important candidate gene for PBD due to its important role in bone turnover. In this study, we recruited a total of 1,263 subjects from 402 Chinese nuclear families composed of both parents and at least one daughter, and tested the association of the (CA)(n) polymorphism in intron 4 of the TNFR2 gene with PBD using a more contemporary quantitative transmission disequilibrium test (QTDT). Significant within-family association was detected between the CA16 allele and bone mineral density (BMD) at the lumbar spine with the P-value of 0.005 after permutations, which is still significant after correction for multiple testing. Some evidence of total-family association between the CA16 allele and lumbar spine BMD was found (P=0.021), although the significant level did not reach the empirical threshold (P< or =0.007). About 3.14% of lumbar spine BMD variation can be explained by the CA16 allele. In summary, our results suggest that the TNFR2 gene may play an important role in determining lumbar spine BMD variation in Chinese women.
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2,337,596 |
Short tandem repeats haplotyping of the HLA region in preimplantation HLA matching.
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Recently, preimplantation genetic diagnosis (PGD) has been considered for several indications beyond its original purpose, not only to test embryos for genetic disease but also to select embryos for a nondisease trait, such as specific human leukocyte antigen (HLA) genotypes, related to immune compatibility with an existing affected child in need of a haematopoetic stem cell (HSC) transplant. We have optimized an indirect single-cell HLA typing protocol based on a multiplex fluorescent polymerase chain reaction (PCR) of short tandem repeat (STR) markers scattered throughout the HLA complex. The assay was clinically applied in 60 cycles from 45 couples. A conclusive HLA-matching diagnosis was achieved in 483/530 (91.1%) of the embryos tested. In total, 74 (15.3%) embryos revealed an HLA match with the affected siblings, 55 (11.4%) of which resulted unaffected and 46 (9.5%) have been transferred to the patients. Nine pregnancies were achieved, five healthy HLA-matched children have already been delivered and cord blood HSCs, were transplanted to three affected siblings, resulting in a successful haematopoietic reconstruction.
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2,337,597 |
In vivo characterization of a vertebrate ultraconserved enhancer.
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Genomic sequence comparisons among human, mouse, and pufferfish (Takifugu rubripes (Fugu)) have revealed a set of extremely conserved noncoding sequences. While this high degree of sequence conservation suggests severe evolutionary constraint and predicts a lack of tolerance to change to retain in vivo functionality, such elements have been minimally explored experimentally. In this study, we describe the in-depth characterization of an ancient conserved enhancer, Dc2, located near the dachshund gene, which displays a human-Fugu identity of 84% over 424 basepairs (bp). In addition to this large overall conservation, we find that Dc2 is characterized by the presence of a large block of sequence (144 bp) that is completely identical among human, mouse, chicken, zebrafish, and Fugu. Through the testing of reporter vector constructs in transgenic mice, we observed that the 424-bp Dc2-conserved element is necessary and sufficient for brain tissue enhancer activity. In vivo analyses also revealed that the 144-bp 100% conserved sequence is necessary, but not sufficient, to replicate Dc2 enhancer function. However, the introduction of two separate 16-bp insertions into the highly conserved enhancer core did not cause any detectable modification of its in vivo activity. Our observations indicate that the 144-bp 100% conserved element is tolerant of change at least at the resolution of this transgenic mouse assay and suggest that purifying selection on the Dc2 sequence might not be as strong as we predicted or that some unknown property also constrains this highly conserved enhancer sequence.
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2,337,598 |
Sensitive multistep clinical molecular screening of 180 unrelated individuals with retinoblastoma detects 36 novel mutations in the RB1 gene.
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Retinoblastoma (RB) is a neoplasm of retinal origin caused by mutations in RB1, the retinoblastoma tumor suppressor gene. To facilitate genetics counseling and patient management, we adopted a multistep molecular screening assay for detecting RB1 mutations. This assay included DNA sequencing to identify mutations within coding exons and immediate flanking intronic regions, Southern blot analysis to characterize genomic rearrangements, and transcript analysis to characterize potential splicing mutations buried within introns. In a pilot investigation of 180 patients from North America, we identified germline RB1 mutations in 77 out of 85 bilateral RB patients (91%), 7 out of 10 familial unilateral (70%), and 6 out of 85 unilateral patients with no family history of RB (7%). Mutations included 36 novel alterations spanning the entire RB1 gene. Seven of these novel changes were missense or silent mutations. Sequence analysis predicted that, in five out of seven cases, the changes can cause aberrant splicing. This was confirmed by transcript analysis in four out of five cases. In addition, four intronic point mutations within nonconsensus sites activated cryptic splice sites. Without the transcript analysis, the significance of these 11 mutations would have remained undefined. In a separate investigation of a subset of unilateral RB tumors, we identified somatic biallelic RB1 gene inactivation in 34 out of 56 cases (61%) cases. In 14 tumors, only one of the two RB1 mutations could be detected, and in eight tumors, no mutations were detected. The absence of detectable RB1 mutations in eight bilateral cases and eight unilateral tumors suggests that alternative genetic mechanisms may underlie the development of RB in certain individuals.
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2,337,599 |
Identifying nineteenth century genealogical links from genotypes.
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We have developed a likelihood method to identify moderately distant genealogical relationships from genomewide scan data. The aim is to compare the genotypes of many pairs of people and identify those pairs most likely to be related to one another. We have tested the algorithm using the genotypes of 170 Tasmanians with multiple sclerosis recruited into a haplotype association study. It is estimated from genealogical records that approximately 65% of Tasmania's current population of 470,000 are direct descendants of the 13,000 female founders living in this island state of Australia in the mid-nineteenth century. All cases and four to five relatives of each case have been genotyped with microsatellite markers at a genomewide average density of 4 cM. Previous genealogical research has identified 51 pairwise relationships linking 56 of the 170 cases. Testing the likelihood calculation on these known relative pairs, we have good power to identify relationships up to degree eight (e.g. third cousins once removed). Applying the algorithm to all other pairs of cases, we have identified a further 61 putative relative pairs, with an estimated false discovery rate of 10%. The power to identify genealogical links should increase when the new, denser sets of SNP markers are used. Except in populations where there is a searchable electronic database containing virtually all genealogical links in the past six generations, the algorithm should be a useful aid for genealogists working on gene-mapping projects, both linkage studies and association studies.
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