The power of linkage analysis of a disease-related endophenotype using asymmetrically ascertained sib pairs.

A linkage study of a qualitative disease endophenotype in a sample of sib pairs, consisting of one disease affected proband and one sibling is considered. The linkage statistic compares marker allele sharing with the proband in siblings with an abnormal endophenotype to siblings with the normal endophenotype. Expressions for the distribution of this linkage statistic, in terms of the recombination fraction are derived and (1) the genetic parameter values (allele frequency and endophenotype and disease penetrance) and (2) the abnormal endophenotype rates in the population and in classes of relatives of disease affected probands.

Social isolation and depression predict 12-month outcomes in the "waiting for a new heart study".

Background: Identification of modifiable psychosocial characteristics related to survival of heart transplant (HTx) candidates is needed to prevent clinical deterioration and improve prognosis.

Methods: A multi-site, prospective study was conducted with 318 HTx candidates (18% female, 82% male; 53 +/- 11 years of age) newly listed at 17 hospitals in Germany and Austria. Baseline demographic and psychosocial characteristics were assessed by questionnaires.

A Bayesian approach for applying Haseman-Elston methods.

The main goal of this paper is to couple the Haseman-Elston method with a simple yet effective Bayesian factor-screening approach. This approach selects markers by considering a set of multigenic models that include epistasis effects. The markers are ranked based on their marginal posterior probability.

Characteristics of replicated single-nucleotide polymorphism genotypes from COGA: Affymetrix and Center for Inherited Disease Research.

Genetic Analysis Workshop 14 provided re-genotyped single-nucleotide polymorphism (SNP) data. Specifically, both Center for Inherited Disease Research (CIDR) and Affymetrix genotyped the same 11,560 SNPs from the Affymetrix GeneChip Mapping 10K Array marker set on the same 184 individuals from the Collaborative Study on the Genetics of Alcoholism database. While the inconsistency rate between CIDR and Affymetrix (two different genotypes for the same subject) was low (0.

A power study of bivariate LOD score analysis of a complex trait and fear/discomfort with strangers.

Complex diseases are often reported along with disease-related traits (DRT). Sometimes investigators consider both disease and DRT phenotypes separately and sometimes they consider individuals as affected if they have either the disease or the DRT, or both. We propose instead to consider the joint distribution of the disease and the DRT and do a linkage analysis assuming a pleiotropic model.