ALLELIC ASSOCIATION ANALYSIS OF THE 5-HT2C RECEPTOR GENE IN BIPOLAR AFFECTIVE-DISORDER

We have examined a structural variant of the 5-HT2C receptor (Cys23Ser ) for allelic association with bipolar affective disorder in 88 cases and 113 controls. Overall, there was no significant difference in alle le frequencies between the two groups, indicating that the 5-HT2C gene is not a major risk factor for bipolar affective disorder. However, w hen the subjects were analysed according to sex, there was a small exc ess of the serine ser23 allele in female cases (P = 0.04) and this eff ect was also seen if the ser23 allele was considered recessive (P = 0. 03). A small increase in significance was found if only female cases w ith a known family history were included (P = 0.01). These results sug gest that the ser23 allele may increase susceptibility to bipolar affe ctive disorder in women.