Genome-wide linkage analysis in a general population sample using sigma(2)(A) random effects (SSARs) fitted by Gibbs sampling

We used variance components analysis to investigate the underlying determin ants of the quantitative phenotypes (Q1-Q5) and their interrelationships in replicate 42 of the Genetic Analysis Workshop 12 simulated general populat ion. Variance components models were fitted using Gibbs sampling in WinBUGS v1.3. Sigma-squared-A-random-effects (SSARs) were estimated for each pheno type, and were used as derived phenotypes in subsequent linkage analyses. W hole-genome, multipoint linkage analyses were based upon a new Haseman-Elst on identity-by descent sib-pair method that takes a weighted combination of the trait-sum and trait-difference. The five quantitative traits simulated were closely correlated with each other and with affection status. The who le-genome screen of quantitative traits associated with the simulated compl ex disease suggested that one or more major loci regulating Q1 localizes to chromosome 2p and that one or more major loci regulating Q5 may localize t o chromosome 1p. (C) 2001 Wiley-Liss, Inc.