Search results for "Allele"
showing 10 items of 1006 documents
Identifying genetic risk variants for coronary heart disease in familial hypercholesterolemia: an extreme genetics approach
2015
Mutations in the low-density lipoprotein receptor (LDLR) gene cause familial hypercholesterolemia (FH), a disorder characterized by coronary heart disease (CHD) at young age. We aimed to apply an extreme sampling method to enhance the statistical power to identify novel genetic risk variants for CHD in individuals with FH. We selected cases and controls with an extreme contrast in CHD risk from 17 000 FH patients from the Netherlands, whose functional LDLR mutation was unequivocally established. The genome-wide association (GWA) study was performed on 249 very young FH cases with CHD and 217 old FH controls without CHD (above 65 years for males and 70 years of age for females) using the Ill…
Influence of the APOA5 locus on plasma triglyceride, lipoprotein subclasses, and CVD risk in the Framingham Heart Study
2004
Several polymorphisms in the APOA5 gene have been associated with increased plasma triglyceride (TG) concentrations. However, associations between APOA5 and lipoprotein subclasses, remnant-like particles (RLPs), and cardiovascular disease (CVD) risk have been less explored. We investigated associations of five APOA5 single-nucleotide polymorphisms (SNPs; −1131T>C, −3A>G, 56C>G IVS3+ 476G>A, and 1259T>C) with lipoprotein subfractions and CVD risk in 1,129 men and 1,262 women participating in the Framingham Heart Study. Except for the 56C>G SNP, the other SNPs were in significant linkage disequilibria, resulting in three haplotypes (11111, 22122, and 11211) representing 98% of the population.…
The HLA locus and multiple sclerosis in Sicily
2005
The authors report the analysis of HLA-class II allelic heterogeneity in a well characterized multiple sclerosis (MS) Sicilian dataset. Family-based association analysis revealed evidence for excess transmission to affected individuals for alleles HLA-DRB1*1501, DRB1*04, and DQB1*0302. When analyzed as haplotypes, the authors observed excess transmission for the DRB1*0400-DQB1*0302 haplotype. Sicilian patients share the HLA-DRB1*1501 susceptibility allele with affecteds living in continental Italy, but also display the allelic heterogeneity that characterizes Mediterranean populations.
Mutational screening of the USH2A gene in Spanish USH patients reveals 23 novel pathogenic mutations
2011
Abstract Background Usher Syndrome type II (USH2) is an autosomal recessive disorder, characterized by moderate to severe hearing impairment and retinitis pigmentosa (RP). Among the three genes implicated, mutations in the USH2A gene account for 74-90% of the USH2 cases. Methods To identify the genetic cause of the disease and determine the frequency of USH2A mutations in a cohort of 88 unrelated USH Spanish patients, we carried out a mutation screening of the 72 coding exons of this gene by direct sequencing. Moreover, we performed functional minigene studies for those changes that were predicted to affect splicing. Results As a result, a total of 144 DNA sequence variants were identified.…
HLA and killer cell immunoglobulin-like receptors influence the natural course of CMV infection.
2014
Background. Natural killer (NK) cells provide a major defense against cytomegalovirus (CMV) infection through the interaction of their surface receptors, including the activating and inhibitory killer immunoglobulinlike receptors (KIRs), and human leukocyte antigens (HLA) class I molecules. This study assessed whether the KIR and HLA repertoire may influence the risk of developing symptomatic or asymptomatic disease after primary CMV infection in the immunocompetent host. Methods. Sixty immunocompetent patients with primary symptomatic CMV infection were genotyped for KIR and their HLA ligands, along with 60 subjects with a previous asymptomatic infection as controls. Results. The frequency…
Polymorphisms of cyclo-oxygenases and 5-lipo-oxygenase-activating protein are associated with chronic spontaneous urticaria and urinary leukotriene E4
2011
The mechanisms of chronic spontaneous urticaria (CSU) continue to be unknown. Our working hypothesis is that polymorphisms of cyclo-oxygenases and 5-lipo-oxygenase-activating protein may be involved in the pathways leading to CSU. We examined five candidate polymorphisms of cyclo-oxygenases 1 and 2 and of 5-lipo-oxygenase-activating protein in 109 controls and in 94 CSU patients from Northern Italy. We also examined the levels of urinary leukotriene E4 (LTE4) before and after challenge with ASA. A multiple regression model was found to show that COX-2 5'UTR T/G, COX-2 Exon 10 T/C, and FLAP -336 G/A polymorphisms were significantly associated with CSU, with the minor allele more represented …
Relationship Between Human Leucocyte Antigen Class I and Class II and Chronic Idiopathic Urticaria Associated With Aspirin and/or NSAIDs Hypersensiti…
2006
Background. HLA genes play a role in the predisposition of several diseases. The aim was to analyze the prevalence of HLA class I phenotypes and HLA-DRB1*genotype in patients with CIU associated with ASA and NSAIDs hypersensitivity (AICU).Methods. 69 patients with AICU, and 200 healthy subjects.Results. Subjects with HLA-B44 and HLA-Cw5 antigens were more represented in patients with AICU than in control group. Subjects with HLA-A11, HLA-B13, HLACw4, and HLA-Cw7 antigen were more represented in control group than in patients with AICU. Multiple logistic regression demonstrated an association of HLA-Cw4 and HLA-Cw7 with a lower risk of AICU, whereas carriers of HLA-B44 phenotype had a higher…
Role of TLR4 Receptor Polymorphisms in Boutonneuse Fever
2005
The genetics of the interaction between host and microbes plays an essential role in the survival of the individual and attainment of longevity. The activation of toll-like receptor (TLR)4 plays a key role in natural and clonotypic immune responses. We evaluated whether TLR4 genotype is a component of genetic background protective versus rickettsiosis and whether this background influences longevity. We genotyped for +896A/G TLR4 polymorphism 78 patients affected by Boutonneuse fever, 78 age-matched controls and 78 advanced age individuals from Sicily. The +869G allele, that attenuates receptor signalling, was significantly overrepresented in patients in comparison with age-matched control…
Association between the TaqIB polymorphism in the cholesteryl ester transfer protein gene locus and plasma lipoprotein levels in familial hypercholes…
2001
Abstract Cholesteryl ester transfer protein (CETP) facilitates the exchange of triglycerides (TG) and cholesteryl ester between lipoprotein particles. Subjects with familial hypercholesterolemia (FH) have been reported to have higher CETP activities, which could contribute to the lower high-density lipoprotein-cholesterol (HDL-C) levels and increased cardiovascular risk observed in some of these patients. Several polymorphisms have been reported in the CETP locus; the common TaqlB polymorphism is associated, in normolipidemic subjects, with decreased CETP activity and levels and with increased HDL-C levels. No data is available on the influence of this polymorphism in FH subjects. We have e…
Analysis of genetic variations of protein tyrosine kinase fyn and their association with alcohol dependence in two independent cohorts.
2003
Abstract Background Decreased sensitivity to and increased tolerance for the effects of alcohol is a phenotype, which was shown to be associated with an increased risk for alcoholism in humans and was observed in protein tyrosine kinase (PTK) fyn knockout mice. Methods We performed an association study of genetic variations of PTK fyn in 430 alcohol-dependent patients and 365 unrelated control subjects from two independent samples. Results In a combined analysis, we found an association of alcohol dependence with the single nucleotide polymorphism (SNP) T137346C in the 5′ untranslated region (UTR) of the gene. A relevant association could be excluded for the remaining two informative SNPs. …