|
| ||
|
|
||
Candidate Polymorphisms (candidate + polymorphism)
Selected AbstractsThe concordance test emerges as a powerful tool for identifying quantitative trait nucleotides: lessons from BTA6 milk yield QTLANIMAL GENETICS, Issue 2 2009E. Seroussi Summary The lack of conventions for confirming the discovery of quantitative trait nucleotides in livestock was evidenced by the proposals of mutations in two different genes (SPP1 and ABCG2) as the underlying functional mutation for a major quantitative trait locus (QTL) for milk concentration on bovine chromosome 6 (BTA6). Of these conflicting candidates, SPP1 was excluded by follow-up studies and by the data described here. A simple test for concordance of the zygosity state between QTL segregation status and the candidate polymorphism was shown, in this case, to be a critical step towards establishing the proof. If a given sample effectively represents the genetic variation across the QTL region, haplotype-based concordance may further enhance the functionality and resolution power of this test, allowing identification of the causative gene. [source] GENETIC STUDY: Tryptophan hydroxylase 2 gene and alcohol use among college studentsADDICTION BIOLOGY, Issue 3-4 2008Paul Gacek ABSTRACT Genes that regulate serotonin activity are regarded as promising predictors of heavy alcohol use. Tryptophan hydroxylase (TPH2) plays an important role in serotonergic neurotransmission by serving as the rate-limiting enzyme for serotonin biosynthesis in the midbrain and serotonergic neurons. Despite the link between TPH2 and serotonergic function, TPH2's role in the pathogenesis of alcohol-use disorders remains unclear. The goal of this study was to examine whether a variation in the TPH2 gene is associated with risky alcohol consumption. Specifically, this study examined whether the TPH2 G-703T polymorphism predicted alcohol consumption among college students. In two successive years, 351 undergraduates were asked to record their alcohol use each day for 30 days using an Internet-based electronic diary. Participants' DNA was collected and polymerase chain reaction genotyping was performed. Results show that alcohol consumption was not associated with the TPH2 G-703T polymorphism alone, or the interaction of TPH2 with two other candidate polymorphisms (TPH1 C218A and the SLC6A4 tri-allelic 5-HTTLPR), or negative life events. In conclusion, this study supports recent null findings relating TPH2 to drinking outcomes. It also extends these findings by showing null interactions with the TPH1 C218A polymorphism, the SLC6A4 tri-allelic 5-HTTLPR polymorphism and environmental stressors in predicting sub-clinical alcohol use among Caucasian American young adults. [source] Role of PAX2 gene polymorphisms in Henoch,Schonlein purpura nephritisNEPHROLOGY, Issue 1 2006ZHU-WEN YI SUMMARY: Objective: To investigate the distribution of polymorphisms in the PAX2 gene in children with Henoch,Schonlein purpura with and without nephritis (HSPN and HSP, respectively), with particular attention to the relationship between PAX2 gene polymorphisms and the development of kidney pathology. Methods: Genomic DNA was extracted from the peripheral leukocytes of 39 HSPN patients, 23 HSP patients without nephritis and 100 normal children, and three known single nucleotide polymorphisms (SNP), including 1410C>T, 1521A>C and 1544C>T in exon 8 and exon 9 of the PAX2 gene were studied as the candidate polymorphisms. The above two exons were amplified, the polymerase chain reaction (PCR) products were detected by denatured high-pressure liquid chromatography and direct DNA sequencing was performed for sequences with abnormal elution peaks. Results: In all samples confirmed by direct sequencing, we identified two SNP, which present as complete linkage haplotype 1410C>T + 1521A>C, in exon 8. We did not identify any SNP in exon 9. The frequency of the PAX2 heterozygous genotype 1410CT/1521AC in the HSPN group (28.20%) was significantly higher than in the HSP without HSPN group (4.35%) or in the control group (12.00%) (P < 0.05). The odds ratio (OR) values for HSPN and HSP were 6.05 and 2.62, respectively, and the 95% confidence intervals (CI) were 1.23,29.78 and 1.09,6.30, respectively. However, no differences in the frequency distribution was found between the HSP without nephritis and normal groups. Furthermore, there was no significant correlation between the polymorphism and clinical manifestation or kidney pathology in the HSPN group (P > 0.05). Conclusion: The 1410CT/1521AC PAX2 genotype does not increase susceptibility for HSP, but is likely to increase the susceptibility of kidney involvement, resulting in a HSPN diagnosis. [source] Genetic association study of the GNB3 C825T, the ACE I/D and the eNOS G894T polymorphisms and the risk to develop erectile dysfunction in a German ED populationANDROLOGIA, Issue 4 2010A. Eisenhardt Summary Erectile dysfunction (ED) is often associated with cardiovascular disorders such as hypertension, coronary heart disease, hypercholesterolaemia and diabetes mellitus. The genotypes in the GNB3 C825T, the ACE I/D and the eNOS G894T polymorphisms have been identified as genetic risk factors for cardiovascular disorders. The association between the genotypes in these polymorphisms and the risk to develop ED was analysed. In 455 German ED patients and 111 age-matched healthy controls genotyping in the candidate polymorphisms was performed after DNA extraction from whole blood. Association studies between the genotype distribution in the control group in comparison with the ED-group and age of onset of the disease as well as erectile response to intracorporal prostaglandin injection in dependence of candidate polymorphism genotype were performed using the SPSS-SoftwareŽ. Genotype distribution of the GNB3 C825T, the ACE I/D and the eNOS G894T polymorphisms was similar in the ED population and the healthy control group. The age of onset of the disease as well as the erectile response to intracorporal prostaglandin injection was independent of the genotypes in the three candidate polymorphisms. In contrast to the previous studies in this analysis, the risk to develop ED is not influenced by the genotypes in the GNB3 C825T, the ACE I/D and the eNOS G894T polymorphisms. [source] Genetic profile of ischemic cerebrovascular disease and carotid stenosisACTA NEUROLOGICA SCANDINAVICA, Issue 3 2008K. Kostulas Objectives,,, Carotid artery stenosis (CS) is a major risk factor for ischemic cerebrovascular disease (ICVD) and is therefore of interest in genetic investigating. Here we report the distribution of 100 polymorphisms in 47 suspected susceptibility genes for ICVD and its risk factors. Materials and methods,,, Previously published markers in suspected susceptibility genes were genotyped in ICVD patients and controls (928/602). Genotyping was performed using multiplex polymerase chain reaction (PCR) and linear immobilized probe array assays. ICVD cases were subtyped according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) or subdivided into CS and non-CS patients by ultrasonography in a separate analysis. Results,,, Three polymorphisms located in the lipoprotein lipase (LPL), angiotensinogen (AGT) and guanine nucleotide-binding protein beta-3 (GNB3) genes were significantly associated with ICVD after correction for age and gender. The strongest association was found for the protective LPL Ser447Term polymorphism. All the significant markers showed varying frequencies in different subphenotypes of ICVD. Factor VII, apolipoprotein E and two renin polymorphisms were differentially frequent in patients with evidence of CS compared with non-CS patients. Conclusions,,, We have found that some previously described susceptibility polymorphisms are weakly associated with ICVD and that subdivision of patients into CS and non-CS groups may help to identify new candidate polymorphisms. [source] | |||||||||||||