While positive associations between TH and bipolar affective disorder have been found in several studies, many studies have failed to reproduce these results.
We attempted to test the hypothesis that there was allelic association between polymorphisms around the tyrosine hydroxylase locus and bipolar affective disorder.
These results provide some support for linking affective disorder to this genetic region and suggest that additional linkage and association studies should be conducted to determine whether tyrosine hydroxylase or a nearby locus contributes to susceptibility to bipolar affective disorder in some families.
We have searched for a possible association between polymorphic DNA markers of two candidate genes (tyrosine hydroxylase, TH; dopamine D2 receptor gene, DRD2) and BP in a population from central Spain.
The candidate genes tyrosine hydroxylase (TH) and the dopamine D4 receptor gene (DRD4) are both located in the 11p15.5 region, thus creating strong interest in this region for genetic studies of bipolar affective disorder.
Genetic studies have attempted to link (bipolar) affective disorder to the short arm of chromosome 11 (where the loci for insulin, insulin growth factor (IGF), tyrosine hydroxylase (TH) and h-ras-oncogene are located) but these have failed.