Adjacent genetic markers on chromosome 11p15.5 at or near the tyrosine hydroxylase locus that show population linkage disequilibrium with each other do not show allelic association with bipolar affective disorder

Background, Linkage and association studies have suggested genetic suscepti bility to bipolar affective disorder in a region of chromosome 11 around th e tyrosine hydroxylase locus. We attempted to test the hypothesis that ther e was allelic association between polymorphisms around the tyrosine hydroxy lase locus and bipolar affective disorder. Methods. A case-control association study was employed using four polymorph ic markers, which span a region of approximately 2 cM across the tyrosine h ydroxylase locus. Results. No evidence for allelic association between bipolar affective diso rder and any of these markers was found. However, linkage disequilibrium be tween the markers was detected. Conclusions. This finding diminishes the probability that genes in this reg ion influence susceptibility to bipolar affective disorder, at least in our sample.