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.