Intronic Polymorphism of Tryptophan Hydroxylase and Serotonin Transporter: Indication for Combined Effect in Predisposition to Suicide

Owing to the assumed functionality of intronic polymorphisms of tryptophan hydroxylase (218AC) and 5-hydroxytryptamine transporter (VNTR-2) genes, the authors investigated frequencies of occurrence of the tryptophan hydroxylase & 5-hydroxytryptamine transporter genotypes containing lower activity alleles in 192 suicide victims & 377 controls. Significant differences in frequences of these genotype combinations were found between suicide victims & controls with a clear dose-effect of the suspected genotypes. Concurrent presence of the two variants of these genes seems to be in some kind of relation to the increased susceptibility to suicide. (18 refs.) JA