SumLINK statistic for linkage analysis: application to the ICPCG pooled linkage resource

We propose a novel, genome-wide, linkagebased statistic, "sumLINK," for identification of disease susceptibility loci. Our approach focuses primarily on "linked" pedigrees (those with pedigree-specific LOD ? 0.588; equivalent to unadjusted p ? 0.05) to identify regions of extreme consistency across powerful pedigrees. The sumLINK statistic is simply the sum of multipoint LOD scores for linked pedigrees at a given point in the genome. The genetic factors underlying many complex human traits are poorly understood. Linkage findings are often difficult to replicate, and localizing the genes responsible for linkage signals is challenging. We believe that focusing on individually powerful pedigrees may give the greatest opportunity to identify and localize true susceptibility loci and the underlying genes.