Association between Obsessive-Compulsive Disorder and Serotonin Transporter Gene Polymorphism

Objectives: The definite cause of obsessive-compulsive disorder (OCD) is still unknown. Evidences from familial, twin and segregation studies support the role of a genetic factor. There also are growing evidences indicating that OCD has specific neurochemical and neuroanatomical basis. Derived from the effectiveness of serotonin reuptake inhibitors in OCD treatment, several candidate genes related to serotonin regulation have been hypothesized to play on important role in the development of OCD. One of them is the serotonin transporter gene. The aim of this study was to investigate the association between serotonin transporter gene and OCD. Methods: 124 OCD patients and 119 normal controls participated in this study. Genomic DNA was extracted from their blood. The genotypes and allele frequencies of the 5-HTTLPR polymorphism between OCD group and control group were compared. And we investigated the association between 4 factors derived from YBOCS checklists and 5-HTTLPR polymorphism. Results: In this case-control study, we could not find any association between 5-HTRLPR polymorphism and development of OCD. In OCD group, patients with L (l/s+s/s) genotype had higher scores for the religious/somatic factor than those with S genotype. Conclusion: In this study, there was no difference in genotype distributions of 5-HTTLPR between OCD and control groups. But, L genotype of 5-HTTLPR polymorphism had negative effects on some factors of the obsessive-compulsive symptoms.ope