Full-genome scan for linkage in 50 families segregating the bipolar affective disease phenotype

A genome scan of similar to 12-cM initial resolution was done on 50 of a se t of 51 carefully ascertained unilineal multiplex families segregating the bipolar affective disorder phenotype. In addition to standard multipoint li nkage analysis methods, a simultaneous-search algorithm was applied in an a ttempt to surmount the problem of genetic heterogeneity. The results reveal ed no linkage across the genome. The results exclude monogenic models and m ake it unlikely that two genes account for the disease in this sample. Thes e results support the conclusion that at least several hundred kindreds wil l be required in order to establish linkage of susceptibility loci to bipol ar disorder in heterogeneous populations.