Background. Linkage and association studies have suggested genetic susceptibility to bipolar affective disorder in a region of chromosome 11 around the tyrosine hydroxylase locus. We attempted to test the hypothesis that there was allelic association between polymorphisms around the tyrosine hydroxylase locus and bipolar affective disorder.
Methods. A case–control association study was employed using four polymorphic markers, which span a region of approximately 2 cM across the tyrosine hydroxylase locus.
Results. No evidence for allelic association between bipolar affective disorder and any of these markers was found. However, linkage disequilibrium between the markers was detected.
Conclusions. This finding diminishes the probability that genes in this region influence susceptibility to bipolar affective disorder, at least in our sample.