Multipoint oligogenic linkage analysis of quantitative traits.

We present an overview of pedigree-based variance component linkage methods and discuss their extension to oligogenic inheritance. As an example, oligogenic linkage analyses were performed using the quantitative trait Q4 from the GAW10 simulated data set. A strategy involving sequential oligogenic analyses was found to have increased power to detect the three quantitative trait loci (QTL) influencing Q4 when compared to the classical marginal approach of requiring each locus to have a lod score > or = 3. However, it is shown that requiring conditional lod scores > or = 3 in the sequential analyses may be overly conservative and alternative criteria for the acceptance of multilocus models are discussed.