engleski

Tryptophan hydroxylase gene polymorphism (A218C) in violent suicide victims: age and sex influences

Tryptophan hydroxylase (TPH) is the rate limiting enzyme in the serotonin biosynthesis pathway. Genetic variants of this enzyme have been associated with suicidal behavior, aggression and psychiatric illnesses. In this study we investigated the association of TPH A218C polymorphism with the most severe form of suicidal behavior – violent suicide completion. A relatively large sample of violent suicide victims (N=120) and respective healthy controls (N=120) were genotyped by polymerase chain reaction amplification followed by digestion with restriction enzyme BfaI. Both groups belonged to Croatian ethnical population. Subjects committed suicide by hanging (51.7%), shooting (29.2%), jumping (9.2%), penetrating lesions (5.8%), CO poisoning (2.5%), drowning (0.8%) and train (0.8%). The frequency of CC genotype was higher among suicide victims than among control subjects (Fisher’s Exact Test, two sided, p=0.0322). The mentioned difference was the most pronounced among victims whose age at the suicide completion was over 65 years (Fisher’s Exact Test, two sided p=0.0024). In the group of victims whose age at the suicide completion was over 30 years, as well as in overall female victims, the increase of CC genotype frequency was paralleled with, also significantly, increased C allele frequency. Results indicated that the TPH gene or a gene in its vicinity could influence the risk for violent suicide, and that the influence might be more pronounced among females and older population.

tryptophan hydroxylase; gene polymorphism; suicide

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