Associations between polymorphic variants of the tryptophan hydroxylase 2 gene and obsessive-compulsive disorder

objective: a substantial body of evidence suggests that obsessive-compulsive disorder has a genetic component, and substantial candidate genes for the disorder have been investigated through association analyses. a particular emphasis has been placed on genes related to the serotonergic system, which is likely to play an important role in the pathogenesis of obsessive-compulsive disorder. the gene for tryptophan hydroxylase 2, which is a rate limiting enzyme in serotonin synthesis, is considered an important candidate gene associated with psychiatric disorders. method: our sample consisted of 321 subjects (107 diagnosed with obsessive-compulsive disorder and 214 healthy controls), which were genotyped for eight tagsnps (rs4448731, rs4565946, rs11179000, rs7955501, rs10506645, rs4760820, rs1487275 and rs10879357) covering the entire human tryptophan hydroxylase 2 gene. statistical analyses were performed using unphased, version 3.0.12, and haploview？. results: single markers, genotype analysis did not show a significant genetic association with obsessive-compulsive disorder. a significant association between the t-c-t (rs4448731, rs4565946, rs10506645) and c-a-t (rs4565946, rs7955501, rs10506645) haplotypes and obsessive-compulsive disorder was observed, as well as a strong linkage disequilibrium between snps rs4448731 and rs4565946, and snps rs10506645 and 4760820. discussion: our research has not demonstrated the existence of associations between the eight snps of tph2 and obsessive-compulsive disorder. however, two ld and two haplotypes areas were demonstrated, thus suggesting that more studies in tph2 are needed to investigate the role of tryptophan hydroxylase 2 variants in obsessive-compulsive disorder.