Genome-wide linkage scan for the metabolic syndrome: the GENNID study.

In the United States, the metabolic syndrome (MetS) constitutes a major public health problem with over 47 million persons meeting clinical criteria for MetS. Numerous studies have suggested genetic susceptibility to MetS. The goals of this study were (i) to identify susceptibility loci for MetS in well-characterized families with type 2 diabetes (T2D) in four ethnic groups and (ii) to determine whether evidence for linkage varies across the four groups.

Variation in inflammation-related genes and risk of incident nonfatal myocardial infarction or ischemic stroke.

Background: From initiation to plaque rupture, immune system components contribute to atherosclerosis. We investigated variation in inflammation-related genes - interleukin (IL)-1beta, IL-6, C-reactive protein (CRP), IL-10, IL-18, and the tumor necrosis factor (TNF) superfamily [lymphotoxin(LT)-alpha, TNF-alpha, LT-beta] - with respect to nonfatal incident myocardial infarction (MI) or ischemic stroke risk.

Methods And Results: A population-based case-control study recruited postmenopausal and/or hypertensive Group Health members aged 30-79 years.

Renin-angiotensin system haplotypes and the risk of myocardial infarction and stroke in pharmacologically treated hypertensive patients.

The products of the renin-angiotensin system (RAS) play an important role in the pathogenesis of cardiovascular disease. Studies examining RAS gene variants and cardiovascular disease have focused on single-nucleotide polymorphisms (SNPs) rather than haplotypes, which better characterize the patterns of genetic variation. The authors conducted a population-based, case-control study at Group Health (Seattle, Washington) between 1995 and 1999 to determine whether common haplotypes in the angiotensinogen gene (AGT), the renin gene, the angiotensin-converting enzyme gene, and the angiotensin II receptor type 1 and receptor type 2 genes were associated with the risk of myocardial infarction and stroke among pharmacologically treated hypertensive patients.

Simple estimates of haplotype relative risks in case-control data.

Methods of varying complexity have been proposed to efficiently estimate haplotype relative risks in case-control data. Our goal was to compare methods that estimate associations between disease conditions and common haplotypes in large case-control studies such that haplotype imputation is done once as a simple data-processing step. We performed a simulation study based on haplotype frequencies for two renin-angiotensin system genes.

Comparison of single-nucleotide polymorphisms and microsatellites in detecting quantitative trait loci for alcoholism: the Collaborative Study on the Genetics of Alcoholism.

Background: The feasibility of effectively analyzing high-density single nucleotide polymorphism (SNP) maps in whole genome scans of complex traits is not known. The purpose of this study was to compare variance components linkage results using different density marker maps in data from the Collaborative Study on the Genetics of Alcoholism (COGA). Marker maps having an average spacing of 10 cM (microsatellite), 0.

Genetic Susceptibility to Prostate Cancer: Prostate-specific Antigen and its Interaction with the Androgen Receptor (United States).

Objective: To determine whether directly observed prostate-specific antigen (PSA) promoter diploid haplotype, either alone or in conjunction with androgen receptor (AR) genotype, is associated with prostate cancer risk.

Methods: We conducted a case-control study nested within the US population-based Cardiovascular Health Study cohort. Incident prostate cancers were identified by linkage to cancer registry records for the years 1989-2000.

Sequence variation in NPC1L1 and association with improved LDL-cholesterol lowering in response to ezetimibe treatment.

Niemann-Pick C1-like 1 (NPC1L1) is an intestinal cholesterol transporter and the molecular target of ezetimibe, a cholesterol absorption inhibitor demonstrated to reduce LDL-cholesterol (LDL-C) both as monotherapy and when co-administered with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). Interestingly, significant interindividual variability has been observed for rates of intestinal cholesterol absorption and LDL-C reductions at both baseline and post ezetimibe treatment. To test the hypothesis that genetic variation in NPC1L1 could influence the LDL-C response to ezetimibe, we performed extensive resequencing of the gene in 375 apparently healthy individuals and genotyped hypercholesterolemic patients from clinical trial cohorts.

Genome-wide scan for quantitative trait loci influencing LDL size and plasma triglyceride in familial hypertriglyceridemia.

Small, dense LDLs and hypertriglyceridemia, two highly correlated and genetically influenced risk factors, are known to predict for risk of coronary heart disease. The objective of this study was to perform a whole-genome scan for linkage to LDL size and triglyceride (TG) levels in 26 kindreds with familial hypertriglyceridemia (FHTG). LDL size was estimated using gradient gel electrophoresis, and genotyping was performed for 355 autosomal markers with an average heterozygosity of 76% and an average spacing of 10.

Genetics of gene expression surveyed in maize, mouse and man.

Treating messenger RNA transcript abundances as quantitative traits and mapping gene expression quantitative trait loci for these traits has been pursued in gene-specific ways. Transcript abundances often serve as a surrogate for classical quantitative traits in that the levels of expression are significantly correlated with the classical traits across members of a segregating population. The correlation structure between transcript abundances and classical traits has been used to identify susceptibility loci for complex diseases such as diabetes and allergic asthma.