Search results for "Allele frequency"
showing 10 items of 224 documents
PTPN22 and CTLA-4 Polymorphisms Are Associated With Polyglandular Autoimmunity
2017
Context Single nucleotide polymorphisms (SNPs) of various genes increase susceptibility to monoglandular autoimmunity. Data on autoimmune polyglandular syndromes (APSs) are scarce. Objective Evaluate potential associations of eight SNPs with APSs. Setting Academic referral endocrine clinic. Patients A total of 543 patients with APS and monoglandular autoimmunity and controls. Intervention The SNP protein tyrosine phosphatase nonreceptor type 22 (PTPN22) rs2476601 (+1858); cytotoxic T-lymphocyte‒associated antigen 4 (CTLA-4) rs3087243 (CT60) and rs231775 (AG49); vitamin D receptor (VDR) rs1544410 (Bsm I), rs7975232 (Apa I), rs731236 (Taq I); tumor necrosis factor α rs1800630 (-863); and inte…
Prevalence of methylenetetrahydrofolate reductase 677T and 1298C alleles and folate status: a comparative study in Mexican, West African, and Europea…
2006
Background: Methylenetetrahydrofolate reductase (MTHFR) 677C→T polymorphism is heterogeneously distributed worldwide, with the highest and lowest frequencies of the T allele in Mexico and Africa, respectively, and a south-to-north gradient in Europe. Distribution of MTHFR 1298A→C is less well known. It has been hypothesized that 677T frequency could result in part from gene-nutrient interactions. Objective: The objective was to compare the association of 677T and 1298C alleles with plasma concentrations of homocysteine, folate, and vitamin B-12 in geographical areas with contrasting 677T allele frequencies. Design: Healthy young adults (n = 1:277) were recruited in Mexico City, the West Afr…
Frequency and phenotype of SPG11 and SPG15 in complicated hereditary spastic paraplegia
2009
Background: Hereditary spastic paraplegias (HSP) are clinically and genetically highly heterogeneous. Recently, two novel genes, SPG11 ( spatacsin ) and SPG15 ( spastizin ), associated with autosomal recessive HSP, were identified. Clinically, both are characterised by complicated HSP and a rather similar phenotype consisting of early onset spastic paraplegia, cognitive deficits, thin corpus callosum (TCC), peripheral neuropathy and mild cerebellar ataxia. Objective: To compare the frequency of SPG11 and SPG15 in patients with early onset complicated HSP and to further characterise the phenotype of SPG11 and SPG15. Results: A sample of 36 index patients with early onset complicated HSP and …
The role of IL-1 gene cluster in longevity: a study in Italian population.
2003
In this study, we analysed the polymorphic variants of IL-1alpha (C-T transition at position -889), IL-1beta (C-T transition at position -511) and IL-1 receptor antagonist (Ra) (86-bp repeated sequence in intron 2) in 1131 subjects (453 females and 678 males) from Northern and Central Italy, including 134 centenarians, to evaluate whether IL-1 cluster alleles might be differently represented in people selected for longevity. In addition, IL-1Ra and IL-1beta plasma levels were quantified by ELISA in 130 randomly selected subjects. No significant differences in the genotype and allele frequency distributions were observed between young, elderly and centenarian subjects. IL-1Ra plasma levels s…
Allele frequencies of +874T→A single nucleotide polymorphism at the first intron of interferon-γ gene in a group of Italian centenarians
2002
Ageing is characterized by a pro-inflammatory status which could contribute to the onset of major age-related diseases such as cardiovascular diseases, neurodegeneration, osteoarthritis and osteoporosis, and diabetes. Thus, it can be hypothesized that genetic variations in pro- or anti-inflammatory cytokines might influence successful ageing and longevity. We have studied the distribution of +874T--A interferon-gamma (IFN-gamma) polymorphisms in a large number of Italian centenarians to evaluate if the two alleles might be differently represented in people selected for longevity. DNA samples were obtained from 174 Italian centenarians (99 years old, 142 women and 32 men) and from 24860-year…
PAI-1 plasma levels in a general population without clinical evidence of atherosclerosis: relation to environmental and genetic determinants.
1998
Abstract —Plasminogen activator inhibitor-1 (PAI-1) plasma levels have been consistently related to a polymorphism (4G/5G) of the PAI-1 gene. The renin-angiotensin pathway plays a role in the regulation of PAI-1 plasma levels. An insertion ( I )/deletion ( D ) polymorphism of the angiotensin-converting enzyme (ACE) gene has been related to plasma and cellular ACE levels. In 1032 employees (446 men and 586 women; 22 to 66 years old) of a hospital in southern Italy, we investigated the association between PAI-1 4G/5G and the ACE I/D gene variants and plasma PAI-1 antigen levels. None of the individuals enrolled had clinical evidence of atherosclerosis. In univariate analysis, PAI-1 levels we…
PTK2 rs7460 and rs7843014 polymorphisms and exceptional longevity: a functional replication study
2014
Focal adhesion is critical for cell survival. The focal adhesion kinase (FAK, or PTK2) is an important component of the human interactome and thus is a potential longevity-related protein. Here we studied the association between two PTK2 gene single-nucleotide polymorphisms (SNPs) (rs7843014, rs7460) and exceptional longevity (EL). In addition to gaining insight into their functionality by determining luciferase gene reporter activity, we studied the genotype/allele frequency of these two SNPs among three different cohorts: (1) Spanish centenarians (n=175, 100–111 years, 144 women) and healthy controls (n=355, 20–50 years, 284 women); (2) Italian centenarians (n=79, 100–104 years, 40 women)…
Association between platelet endothelial cellular adhesion molecule 1 (PECAM-1/CD31) polymorphisms and acute myocardial infarction: a study in patien…
2004
Summary Adhesion of circulating cells to the arterial surface is among the first detectable events in atherogenesis. Cellular adhesion molecules, expressed by the vascular endothelium and by circulating leucocytes, mediate cell recruitment and their transendothelial migration. Platelet endothelial cellular adhesion molecule 1 (PECAM-1/CD31), involved in this migration, has been associated with the developmental course of atherosclerosis. A few studies have investigated an association between coronary heart disease and single nucleotide polymorphisms (SNPs) located in functionally important domains of the PECAM-1/CD31 gene. In particular, Ser563Asn and Gly670Arg SNPs have been described as s…
Genome-Wide Association Studies of the PR Interval in African Americans.
2011
The PR interval on the electrocardiogram reflects atrial and atrioventricular nodal conduction time. The PR interval is heritable, provides important information about arrhythmia risk, and has been suggested to differ among human races. Genome-wide association (GWA) studies have identified common genetic determinants of the PR interval in individuals of European and Asian ancestry, but there is a general paucity of GWA studies in individuals of African ancestry. We performed GWA studies in African American individuals from four cohorts (n = 6,247) to identify genetic variants associated with PR interval duration. Genotyping was performed using the Affymetrix 6.0 microarray. Imputation was p…
Array comparative genomic hybridization analysis of chromosomal imbalances and their target genes in gastrointestinal stromal tumors.
2007
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. The tumors characteristically harbor KIT or PDGFRA mutations, and mutant tumors respond to imatinib mesylate (Glivectrade mark). Chromosomal imbalances resulting in altered gene dosage are known to have a role in the molecular pathogenesis of these tumors, but the target genes remain to be identified. The present study aimed to identify some of these genes. In total, 35 GIST samples were screened for chromosomal imbalances by array-based comparative genomic hybridization. A cDNA array was used to define the minimal common overlapping areas of DNA copy number change. Eight confirmative, …