Combined linkage and association sib-pair analysis for quantitative traits

An extension to current maximum-likelihood variance-components procedures f or mapping quantitative-trait loci in sib pairs that allows a simultaneous test of allelic association is proposed. The method involves modeling of th e allelic means for a test of association, with simultaneous modeling of th e sib-pair covariance structure for a test of linkage. By partitioning of t he mean effect of a locus into between- and within-sibship components, the method controls for spurious associations due to population stratification and admixture. The power and efficacy of the method are illustrated through simulation of various models of both real and spurious association.