The results of the present study demonstrated that methylation in the promoter region of TPH2 significantly affected the mRNA expression levels of TPH2, thus suggesting that methylation of the TPH2 promoter may silence TPH2 mRNA expression in MDD patients with or without suicidal behavior.
These findings suggest that TPH2 gene confers risk for suicidal behavior while hopelessness can be a potential endophenotype for suicidal vulnerability.
Our results suggest that the common SNPs and haplotypes of the TPH2 gene are unlikely to contribute to the genetic susceptibility to suicidal behavior in Japanese population.
In this study, we aimed to investigate the association of serotonin 2A receptor gene -1438A/G SNP (HTR2A -1438A/G), tryptophan hydroxylase 2 gene -703G/T SNP (TPH2-703G/T) and serotonin 1A receptor C-1019G (HTR1A C-1019G) with suicidal behavior.