Equivalence between Haseman-Elston and variance-components linkage analyses for sib pairs

The Haseman-Elston regression method offers a simpler alternative to varian ce-components (VC) models, for the linkage analysis of quantitative traits. However, even the "revisited" method, which uses the cross-product-rather than the squared difference-in sib trait values, is, in general, less power ful than VC models. In this report, we clarify the relative efficiencies of existing Haseman-Elston methods and show how a new Haseman-Elston method c an be constructed to have power equivalent to that of VC models. This metho d uses as the dependent variable a linear combination of squared sums and s quared differences, in which the weights are determined by the overall trai t correlation between sibs in a population. We show how this method can be used for both the selection of maximally informative sib pairs for genotypi ng and the subsequent analysis of such selected samples.