Although findings to date are mixed, serotonin transporter polymorphism 5-HTTLPR and HTR2A polymorphism rs6311 (or rs6313) are most consistently associated with OCD.
Previous research shows that OCD is associated with serotonin-related polymorphisms (5-HTTLPR coded as triallelic and HTR2A rs6311/rs6313) and, in males, a polymorphism involved in catecholamine modulation; COMT (rs4680).
A previous study showed that a single nucleotide polymorphism (SNP), -1438G/A (rs6311), found in the transcriptional control region of the gene that encodes the serotonin-receptor 2A (HTR2A) was associated with obsessive-compulsive disorder (OCD) in a sample of children and adolescents.
The purpose of this study is to investigate the association between four serotonergic polymorphisms (STin2 VNTR and 5-HTTLPR of the SLC6A4 gene, and A-1438G (rs6311) and T102C (rs6313) of the HTR2A gene) and OCD.
Nominally significant association was found at the HTR2A rs6311 polymorphism in subjects with tic disorder and OCD (p = .05), replicating a previous finding in Tourette syndrome and OCD.