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.
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.
No association between tryptophan hydroxylase and suicidal behavior was detected.
The tryptophan hydroxylase gene was not a susceptibility factor for suicidal behaviors in the group of suicide attempters in this study.