No Associations between 5-HTT, 5-HT2A gene Polymorphisms and Obsessive-Compulsive Disorder in a Korean Population

This study aimed to investigate the possible associations between candidate single nucleotide polymorphisms (SNPs) in the 5-HTT and 5-HT2A genes and the susceptibility to and clinical features of OCD. We screened the SNPs in the 5-HTT, 5-HT2A and DRD2 genes in one hundred and forty eight healthy volunteers by two dimensional gene scanning (TDGS). We chose candidate SNPs which were newly detected by TDGS or had previously been linked with psychiatric disorders such as schizophrenia or depression. The 5-HTT gene-linked polymorphic region (HTTLPR), 17 bp variable number of tandem repeats in the second intron (VNTR), 878C>T, and 1815A>C SNPs in the 5-HTT gene, and 102T>C SNP in the 5-HT2A gene were analyzed by PCR or PCR-RFLP as appropriate. “One hundred and fifty seven healthy unrelated Korean volunteers were enrolled as a control group.” There were no significant differences in the allele frequencies or genotype distributions between the OCD patients and the control group. However, we found a significant difference in the age of onset according to gender; the males showed an earlier age of onset compared to the females (17.5 6.4 vs. 23.1 11.2 for the males and females, respectively). This investigation failed to produce evidence that the 5-HTT and 5-HT2A polymorphisms influence the risk for OCD in Koreans. The inheritance of OCD is not simple and most likely involves a number of susceptibility genes and environmental influences.