A Variance Component Approach to Dichotomous Trait Linkage Analysis Using a
Threshold Model
Duggirala R, Williams JT, Williams-Blangero S, Blangero J
Division of Clinical Epidemiology, University of Texas Health Science Center at San
Antonio.
Genetic Epidemiology, 14(6):987-992 (1997)
Abstract
We developed and utilized a multipoint variance components method to test for linkage
between a disease trait and markers on chromosome 5 in the simulated data provided in
GAW10 Problem 2. We demonstrated that the discrete trait variance components
method recovers unbiased estimates of quantitative trait locus (QTL) location and
reasonable estimates of effect size. We also showed that dichotomization of (a
continuous trait such as) Q1 diminished the power to detect linkage compared to direct
analysis of Q1, and that extended pedigree analyses provided superior power to detect
linkage compared to those in nuclear families.
Variance component linkage analysis