Background: To determine whether the tryptophan hydroxylase gene (ie, the gene that codes for the rate-limiting enzyme in the metabolic pathway of serotonin) may be a susceptibility factor for suicidal behavior.
Methods: Genotypic and allelic frequencies at a polymorphic Ava II restriction site were revealed with the use of the complementary DNA tryptophan hydroxylase probe C2-38 in 62 suicide attempters. The psychiatric characteristics of these suicide attempters were determined using the Schedule for Affective Disorders and Schizophrenia-Lifetime version with modification for the study of anxiety disorders, and these characteristics were compared with those in 52 healthy controls.
Results: No association between tryptophan hydroxylase and suicidal behavior was detected.
Conclusion: The tryptophan hydroxylase gene was not a susceptibility factor for suicidal behaviors in the group of suicide attempters in this study.