우울장애 환자에서 자살 시도와 트립토판 수산화 효소(Tryptophan Hydroxylase) A218C 유전자 다형성과의 관련성

Association Between Suicide Attempts in Patients With Depressive Disorder and Tryptophan Hydroxylase A218C Polymorphism

Objectives：Several lines of evidence suggest the serotonergic dysfunction involved in the biological susceptibility of suicide. Tryptophan hydroxylase (TPH), the rate-limiting enzyme in the biosynthesis of serotonin, plays a vital role in serotonin metabolism. In a case-control study, we investigated whether the TPH gene was a susceptible factor for suicidal behavior in depressive patients. Methods：The subjects were 218 depressed patients who attempted suicide and visited emergency rooms in multi-medical centers. One hundred thirty hospitalized non-suicidal depressed patients and the 161 normal controls were matched with the suicidal group. Individuals in all 3 groups were evaluated independently by a Structured Clinical Interview for the purpose of establishing a DSM-IV criteria diagnosis (SCID). The severity of depressive symptoms was evaluated using Hamilton depression rating scale (HDRS). Results：There was no significant difference in genotype distributions and allele frequencies of TPH intron 7 A218C polymorphisms among 3 groups. Furthermore, no significant difference in genotype counts and allele frequencies of the polymorphisms was found among lethal suicidal depressed patients, non-suicidal depressed patients and the normal controls. Conclusion：This study suggests that the A218C polymorphism of the TPH gene is unlikely to have a major effect on the susceptibility of suicidal behaviors in depressive patients