engleski

Intronic polymorphisms of tryptophan hydroxylase and serotonin transporter genes in suicide victims

Tryptophan hydroxylase (TPH), as a rate-limiting enzyme of serotonin (5HT) synthesis, and 5HT transporter (5HTt), as a terminator of 5HT synaptic action, represent important regulators of serotonergic neurotransmission. Variants of both protein genes have been associated with sucidal attempts, aggresion and psychiatric illness. In order to further explore the involvement of TPH and 5HTt genes in suicidality, we studied TPH A218C polymorphism in intron 7, and 5HTt VNTR polymorphism in intron 2, in samples of 86 individuals with completed suicide and 91 contols without personal and family history of psychiatric disorders and suicidal behaviour. Both groups belonged to Croatian ethnical population. DNA was obtained from blood samples and genotyped after PCR amplification with specific primers. No significant differences were observed in distribution of 5HTt genotypes or alleles between controls and suicide victims. On the other hand, a significant difference appeared in TPH genotypic distibution between the mentioned groups (c2=7.48, df=2, p<0.05), owing to the higher frequency of CC genotype in suicide victims (odds ratio 2.26). Our results indicate possible involvement of TPH gene (or a gene nearby) in suicidal behaviour and encourage further studies on 5HT synaptic elements in suicide.

tryptophan hydroxylase; serotonin transporter; gene polyporphism; suicidality

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