Genetic variation of the 5-HT2A receptor gene and bipolar affective disorder.

Abnormalities of the serotonergic system have classically been associated with the origin of affective disorders through the biochemical action of therapeutic agents and their role in affective and perceptual states. In the present study, we hypothesized that genetic variation in the 5-hydroxytryptamine (serotonin) type 2A (5-HT2A) receptor gene (HTR2A) might have an effect on the aetiology of bipolar affective disorder. Four different polymorphisms in the HTR2A gene were studied in 88 patients with bipolar affective disorder and 113 healthy controls, all of Spanish origin. No significant association was observed between any of the four polymorphisms at the HTR2A locus, whether tested individually or as haplotypes, and bipolar affective disorder. The lack of association suggests that HTR2A is not a major risk factor for bipolar affective disorder.