A LINKAGE STUDY OF AFFECTIVE-DISORDER WITH DNA MARKERS FOR THE ABO-AK1-ORM LINKAGE GROUP NEAR THE DOPAMINE-BETA-HYDROXYLASE GENE

Combining data from a number of studies has provided evidence for a su sceptibility allele for affective disorder near to the ABO-AK1-ORM reg ion on chromosome 9q34. The dopamine beta hydroxylase gene locus is al so at 9q34. Five multigenerational families with bipolar and unipolar affective disorder were analyzed for linkage with highly polymorphic m icrosatellite markers from the candidate region. The segregation of th e illness in these families ws compatible with an autosomal dominant s usceptibility allele. Linkage analyses using conservative parameters s eemed to provide strong evidence against a major susceptibility allele in this region including the candidate gene dopamine beta hydroxylase in these families.