Search results for "Linkage Disequilibrium"
showing 10 items of 134 documents
Linkage disequilibrium of MTHFR genotypes 677C/T-1298A/C in the German population and association studies in probands with neural tube defects(NTD).
1999
A number of studies have demonstrated that the common polymorphism 677CT in the gene encoding 5, 10-methylenetetrahydrofolate reductase (MTHFR) leads to a thermolabile variant with decreased enzyme activity and to mildly elevated plasma homocysteine. 677TT homozygosity was shown to be more frequent in NTD probands compared with controls in some studies. Recently, another polymorphism, 1298AC, in the MTHFR gene was described and combined heterozygosity 677CT/1298AC was suggested to be an additional risk factor for NTD. The present study examines the genotype and haplotype distribution of the two polymorphisms in the German population and evaluates the impact on NTD individuals and their rela…
Population differences in the International Multi-Centre ADHD Gene Project.
2008
Contains fulltext : 71443.pdf (Publisher’s version ) (Closed access) The International Multi-Centre ADHD Gene sample consists of 674 families from eight countries (Belgium, England, Germany, Holland, Ireland, Israel, Spain, and Switzerland) ascertained from clinics for combined-type attention definity hyperactivity disorder in an offspring. 863 SNPs were successfully genotyped across 47 autosomal genes implicated in psychiatric disorders yielding a single nucleotide polymorphism (SNP) density of approximately one SNP per 2.5 kb. A global test of heterogeneity showed 269 SNPs nominally significant (expected 43). Inclusion of the Israeli population accounted for approximately 70% of these nom…
Gene-environment interactions of CETP gene variation in a high cardiovascular risk Mediterranean population
2010
Genome-wide association studies show that cholesteryl ester transfer protein (CETP) single nucleotide polymorphisms (SNPs) are more strongly associated with HDL cholesterol (HDL-C) concentrations than any other loci across the genome. However, gene-environment interactions for clinical applications are still largely unknown. We studied gene-environment interactions between CETP SNPs and dietary fat intake, adherence to the Mediterranean diet, alcohol consumption, smoking, obesity, and diabetes on HDL-C in 4,210 high cardiovascular risk subjects from a Mediterranean population. We focused on the −4,502C>T and the TaqIB SNPs in partial linkage disequilibrium (D'= 0.88; P < 0.001). They were i…
A whole genome screen for linkage disequilibrium in multiple sclerosis performed in a continental Italian population
2003
We have systematically screened the genome for evidence of linkage disequilibrium (LD) with multiple sclerosis (MS) by typing 6000 microsatellite markers in case-control and family based (AFBAC) cohorts from the Italian population. DNA pooling was used to reduce the genotyping effort involved. Four DNA pools were considered: cases (224 Italian MS patients), controls (231 healthy Italians), index (185 index cases from trio families) and parents (the 370 parents of the patient included in the Index pool), respectively. After refining analysis of the most promising 14 markers to emerge from this screening process, only marker D2S367 retained evidence for association. © 2003 Elsevier B.V. All r…
An ancestral recombination graph for diploid populations with skewed offspring distribution
2013
A large offspring number diploid biparental multilocus population model of Moran type is our object of study. At each timestep, a pair of diploid individuals drawn uniformly at random contribute offspring to the population. The number of offspring can be large relative to the total population size. Similar `heavily skewed' reproduction mechanisms have been considered by various authors recently. Each diploid parental individual contributes exactly one chromosome to each diploid offspring, and hence ancestral lineages can only coalesce when in distinct individuals. A separation of timescales phenomenon is thus observed. A result of M\"{o}hle (1998) is extended to obtain convergence of the an…
Comparison of casein haplotypes between two geographically distant European dairy goat breeds.
2008
The aim of this paper was to characterize the diversity among haplotypes based on 22 single nucleotide polymorphisms (SNPs) and one deletion within four casein genes in two geographically distant goat populations, the Sicilian Girgentana breed and the Norwegian goat breed. Forty Girgentana goats were genotyped for the aforementioned polymorphisms and the resulting data set was compared with 436 goats from the Norwegian population previously genotyped for these markers. Several casein gene polymorphisms were not in Hardy-Weinberg equilibrium either in Girgentana, or in the Norwegian breed. The SNP haplotype frequencies for the four casein genes were calculated and despite the large geographi…
DVWA gene polymorphisms and osteoarthritis
2015
Background: Osteoarthritis (OA) is a degenerative joints disorder influenced by genetic predisposition. We reported that rs11718863 DVWA SNP was represented in Sicilian with a more severe Kellgren and Lawrence (KL) radiographic grade, displaying its predictive role as OA marker progression. Here, we describe the DVWA SNPs: rs11718863, rs7639618, rs7651842, rs7639807 and rs17040821 probably able to induce protein functional changes. Findings: Sixty-one Sicilian patients with knee OA and 100 healthy subjects were enrolled. Clinical and radiographic evaluation was performed using AKSS scores and KL. Linkage Disequilibrium (LD) analyses were performed in order to verify whether the SNPs segrega…
Extended analysis of a genome-wide association study in primary sclerosing cholangitis detects multiple novel risk loci
2012
Background & Aims: A limited number of genetic risk factors have been reported in primary sclerosing cholangitis (PSC). To discover further genetic susceptibility factors for PSC, we followed up on,a second tier of single nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS). Methods: We analyzed 45 SNPs in 1221 PSC cases and 3508 controls. The association results from the replication analysis and the original GWAS (715 PSC cases and 2962 controls) were combined in a meta-analysis comprising 1936 PSC cases and 6470 controls. We performed an analysis of bile microbial community composition in 39 PSC patients by 16S rRNA sequencing. Results: Seventeen SNPs representing 1…
Variation in genes encoding for interferon λ-3 and λ-4 in the prediction of HCV-1 treatment-induced viral clearance
2013
Background & Aims In patients with chronic HCV-1 infection, recent evidences indicate that determination of a dinucleotide polymorphism (ss469415590, ΔG/TT) of a new gene, designated IFN λ-4, might be more accurate than the 12979860CC type of the IL28B locus in predicting sustained virological response (SVR) following peg-interferon and ribavirin. In addition, combined genotyping of different SNPs of the IL28B locus was shown to help dissect patients most prone to SVR among those with rs12979860CT. We examined whether single or combined genotyping of two IL28B SNPs, rs12979860 and rs8099917, and ss469415590 variation might improve the prediction of SVR. Results In the study cohort of 539 pa…
Differential dopamine receptor D4 allele association with ADHD dependent of proband season of birth
2008
Contains fulltext : 70196.pdf (Publisher’s version ) (Closed access) Season of birth (SOB) has been associated with attention deficit hyperactivity disorder (ADHD) in two existing studies. One further study reported an interaction between SOB and genotypes of the dopamine D4 receptor (DRD4) gene. It is important that these findings are further investigated to confirm or refute the findings. In this study, we investigated the SOB association with ADHD in four independent samples collected for molecular genetic studies of ADHD and found a small but significant increase in summer births compared to a large population control dataset. We also observed a significant association with the 7-repeat…