Quantitative trait linkage analysis of the liability underlying a common oligogenic disease

We utilized pedigree discriminant and factor analytic approaches to combine multivariate phenotypic information into a single liability phenotype in t he isolate and general populations. We applied two-stage relative-pair quan titative trait linkage analysis to detect genetic contributions to variatio n in the resulting liability phenotypes. Linkage analysis revealed several regions of suggestive linkage in both the general and isolate populations, the majority of which appear in retrospect to be false positives. A likely explanation is an overall lack of power given that we tested hypotheses in data from only one replicate. However, it may be possible that a construct that ignores affection status when using liability-associated characteristi cs as indicators of this construct is not the most effective approach in mo deling the liability underlying a complex phenotype. (C) 2001 Wiley-Liss, I nc.