Furthermore, the observed association of rs6313 with the familial form of OCD in females suggests different genetic background of OCD familial and non-familial forms, which needs further investigation.
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).
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.