Search results for "Polymorphism"
showing 10 items of 1968 documents
Neural and genetic correlates of antidepressant response to sleep deprivation - A functional magnetic resonance imaging study of moral valence decisi…
2007
Context: Total sleep deprivation combined with light therapy causes rapid amelioration of bipolar depression. A polymorphism in the promoter for the serotonin transporter influences both antidepressant response and the structure and function of specific brain areas. Objective: To determine whether antidepressant therapy or the genotype of the serotonin transporter influence the pattern of neural response to a task targeting the depressive biases in information processing (moral valence decision). Design: Before-and-after trial studying the biologic correlates of response to treatment. Setting: University hospital. Patients: Twenty inpatients with bipolar depression. Intervention: Repeated t…
Genome-wide association study identifies multiple susceptibility loci for diffuse large B cell lymphoma
2014
Diffuse large B cell lymphoma (DLBCL) is the most common lymphoma subtype and is clinically aggressive. To identify genetic susceptibility loci for DLBCL, we conducted a meta-analysis of 3 new genome-wide association studies (GWAS) and 1 previous scan, totaling 3,857 cases and 7,666 controls of European ancestry, with additional genotyping of 9 promising SNPs in 1,359 cases and 4,557 controls. In our multi-stage analysis, five independent SNPs in four loci achieved genome-wide significance marked by rs116446171 at 6p25.3 (EXOC2; P = 2.33 × 10 '21), rs2523607 at 6p21.33 (HLA-B; P = 2.40 × 10 '10), rs79480871 at 2p23.3 (NCOA1; P = 4.23 × 10 '8) and two independent SNPs, rs13255292 and rs47336…
Taxonomic complexity in the halophyte Limonium vulgare and related taxa (Plumbaginaceae): insights from analysis of morphological, reproductive and k…
2014
Part of a special issue on halophytes and saline adaptations Background and Aims Limonium is awell-known example of a group of plants that is taxonomically complex due to certain biological characteristics that hamper species’ delineation. The closely related polyploid species Limonium vulgare Mill., L. humile Mill. and L. narbonense Mill. are defined species and can be used for studying patterns of morphological and reproductive variation. The first two taxa are usually found in Atlantic Europe and the third in the Mediterranean region, but a numberof intermediate morphological formsmay be present alongside typical examples of these species. This study attempts to elucidate morphological, …
Association of ADHD with genetic variants in the 5'-region of the dopamine transporter gene: evidence for allelic heterogeneity.
2008
Contains fulltext : 69953.pdf (Publisher’s version ) (Closed access) Multiple studies have reported an association between attention deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region (3'UTR) of the dopamine transporter gene (DAT1). Yet, recent meta-analyses of available data find little or no evidence for this association; although there is strong evidence for heterogeneity between datasets. This pattern of findings could arise for several reasons including the presence of relatively rare risk alleles on common haplotype backgrounds or the functional interaction of two or more loci within the g…
Accounting for haplotype phase uncertainty in linkage disequilibrium estimation
2007
The characterization of linkage disequilibrium (LD) is applied in a variety of studies including the identification of molecular determinants of the local recombination rate, the migration and population history of populations, and the role of positive selection in adaptation. LD suffers from the phase uncertainty of the haplotypes used in its calculation, which reflects limitations of the algorithms used for haplotype estimation. We introduce a LD calculation method, which deals with phase uncertainty by weighting all possible haplotype pairs according to their estimated probabilities as evaluated by PHASE. In contrast to the expectation-maximization (EM) algorithm as implemented in the HA…
Interethnic studies of TNF polymorphisms confirm the likely presence of a second MHC susceptibility locus in ankylosing spondylitis
2000
The objective of this study was to investigate TNF promoter region polymorphisms for association with susceptibility to ankylosing spondylitis (AS). The TNF -238 and -308 polymorphisms were genotyped in 306 English AS cases and 204 ethnically matched healthy B27-positive controls, and 96 southern German AS cases, 58 B27-positive and 251 B27-negative ethnically matched controls. Additionally, the TNF -376 polymorphism was genotyped in the southern German cases and controls. In the southern German AS patients a significant reduction in TNF -308.2 alleles was seen, compared with B27 positive controls (odds ratio 0.4, P = 0.03, 95% confidence interval 0.2-0.9), but no difference in allele frequ…
Meta-analysis of mismatch repair polymorphisms within the cogent consortium for colorectal cancer susceptibility
2013
In the last four years, Genome-Wide Association Studies (GWAS) have identified sixteen low-penetrance polymorphisms on fourteen different loci associated with colorectal cancer (CRC). Due to the low risks conferred by known common variants, most of the 35% broad-sense heritability estimated by twin studies remains unexplained. Recently our group performed a case-control study for eight Single Nucleotide Polymorphisms (SNPs) in 4 CRC genes. The present investigation is a followup of that study. We have genotyped six SNPs that showed a positive association and carried out a meta-analysis based on eight additional studies comprising in total more than 8000 cases and 6000 controls. The estimate…
Dense genotyping of immune-related disease regions identifies nine new risk loci for primary sclerosing cholangitis
2013
To access publisher's full text version of this article click on the hyperlink at the bottom of the page Primary sclerosing cholangitis (PSC) is a severe liver disease of unknown etiology leading to fibrotic destruction of the bile ducts and ultimately to the need for liver transplantation. We compared 3,789 PSC cases of European ancestry to 25,079 population controls across 130,422 SNPs genotyped using the Immunochip. We identified 12 genome-wide significant associations outside the human leukocyte antigen (HLA) complex, 9 of which were new, increasing the number of known PSC risk loci to 16. Despite comorbidity with inflammatory bowel disease (IBD) in 72% of the cases, 6 of the 12 loci sh…
A tumor necrosis factor-alpha (TNF-alpha) promoter polymorphism is associated with chronic hepatitis B infection.
1998
SUMMARY Cytokines such as TNF-α and interferon gamma (IFN-γ) are important for the elimination of infected hepatocytes during acute hepatitis B virus (HBV) infection. Two G versus A transitions in the TNF-α promoter region at positions −308 and −238 possibly influence TNF-α expression. We investigated these TNF-α polymorphisms in 71 patients with chronic HBV infection, in 32 subjects that had spontaneously recovered from acute HBV infection, and in 99 healthy controls. The −238 A promoter variant was present in 18 (25%) of 71 patients with chronic HBV infection compared with two (6%) of 32 subjects with acute infection (P < 0.04), and seven (7%) of 99 controls (P < 0.003). By …
Genetic signature consistent with selection against the CYP3A4*1B allele in non-African populations.
2005
Cytochrome P450 3A enzymes (CYP3A) play a major role in the metabolism of steroid hormones, drugs and other chemicals, including many carcinogens. The individually variable CYP3A expression, which remains mostly unexplained, has been suggested to affect clinical phenotypes. We investigated the CYP3A locus in five ethnic groups. The degree of linkage disequilibrium (LD) differed among ethnic groups, but the most common alleles of the conserved LD regions were remarkably similar. Non-African haplotypes are few; for example, only four haplotypes account for 80% of common European Caucasian alleles. Large LD blocks of high frequencies were suggestive of selection. Accordingly, European Caucasia…