Association study between 5HT2C receptor gene and affective disorders

Heredity seems to play an important role in the development of affective disorder, while a number of neurotransmitter systems, such as serotoninergic, dopaminergic and gabaergic, have been shown to be implicated in the biology of this illness. Consequently, the genes associated with these systems are considered as candidate for psychiatric genetic research. In order to examine the role of the serotonergic receptor 5HT2C gene, located on chromosome Xq24, in the pathogenesis of affective disorders, we conducted a genetic association study of this gene in 47 bipolar, 38 unipolar patients and 48 healthy individuals. All subjects were Greek, unrelated among them and were personally interviewed; diagnosis was based on DSM-IV and ICD-10 criteria. The molecular analysis was performed by the use of polymerase chain reaction and the products were detected by restrictive enzyme digestion. The genotype frequencies of the gene coding for serotonin receptor 2C were analyzed separately for the two sexes. An association was found between allele 1 of the polymorphism and unipolar affective disorder in women (p=0.002), while no such difference was observed among men (unipolar and bipolar), nor among bipolar women. These finding suggests that the serotonin receptor 5HT2C gene may be implicated in the pathogenesis of unipolar affective disorder.