myocardial infarction (mi) and its major determinant, coronary artery disease (cad), are complex diseases arising from the interaction between several genetic and environmental factors. until recently, the genetic basis of these diseases was poorly understood. genome-wide genetic association studies have afforded a comprehensive insight into the association between genetic variants and diseases...

Variable and person-oriented analyses were used to explore the associations between personality and three previously untested general iris characteristics: crypts, pigment dots and contraction furrows. Personality data, as measured by the NEO PI-R and ratings of iris characteristics from 428 undergraduate students were collected. Crypts were significantly associated with five approach-related b...

Genetic association studies have become an important part of our scientific landscape. This commentary discusses some basic scientific issues which should be considered when reporting and evaluating such studies including SNP Discovery, Genotyping and Haplotype Analysis; Population Size, Matching of Cases and Controls, and Population Stratification; Phenotype Definition and Multiple Related Phe...

The principal component method and the mixed effects model represent two popular approaches to controlling for population structure and cryptic relatedness in genetic association studies. There are only a handful of studies comparing their performance. These studies are typically based on simulation studies and the results are therefore limited in their applicability. In this paper, we conduct ...

The purpose of this review is to focus on the three most important themes in genetic association studies using randomly selected patients (case, affected) and normal samples (control, unaffected), so that students and researchers alike who are new to this field may quickly grasp the key issues and command basic analysis methods. These three themes are: elementary categorical analysis; disease m...

In genetic association studies, investigators compare allele or genotype frequencies in unrelated case and control subjects or examine preferential allele transmissions from parents to affected offspring. In many genetic case-control studies, the collection of DNA material extends to relatives such as parents of cases. Thus, case-control and case-parent trio association analyses are possible. W...

In recent years, progress has been made in the identification of causative factors in most single gene disorders and those with genes of major effect. In comparison, no genes contributing to a complex disorder have been unambiguously identified. A number of reasons for this have been previously presented in theoretical papers. Alcoholism is such a complex illness and genetic studies into its un...

This paper proposes a semiparametric methodology for modeling multivariate and conditional distributions. We first build a multivariate distribution whose dependence structure is induced by a Gaussian copula and whose marginal distributions are estimated nonparametrically via mixtures of B-spline densities. The conditional distribution of a given variable is obtained in closed form from this mu...

Spurious associations due to confounding factors are an often cited and intensely debated concern for genetic association studies. Great attention has been focused upon the specific threat of confounding due to population stratification. This emphasis has spurred the development of many statistical genetic methods to detect and correct for the potentially confounding effects of admixture. Unfor...

Association studies among admixed populations pose many challenges including confounding of genetic effects due to population substructure and heterogeneity due to different patterns of linkage disequilibrium (LD). We use simulations to investigate controlling for confounding by indicators of global ancestry and the impact of including a covariate for local ancestry. In addition, we investigate...