GENETIC EPIDEMIOLOGIC ANALYSIS OF QUANTITATIVE PHENOTYPES USING GIBBSSAMPLING

We analyzed two quantitative traits (Q1 and Q2) provided in the 'Commo n Disease' data set with the aim of detecting both genetic and environ mental determinants. We used linear regression for screening measured variables, maximum likelihood segregation and linkage analyses for det ecting and localizing unmeasured genes, and Gibbs sampling for joint s egregation and linkage analyses with estimation of gene-environment in teraction and polygenic effects. For both Q1 and Q2, we successfully d etected the unmeasured codominant major gene (MG) that was tightly lin ked to candidate gene C2. We also detected all of the measured variabl es used in generating Q1 (age, Q3, candidate gene C5) and Q2 (EF). Alt hough our final models differed slightly from the true data generation models, our multifaceted analytic approach was successful in characte rizing the determinants of Q1 and Q2. (C) 1995 Wiley-Liss, Inc.