Tryptophan hydroxylase polymorphism is associated with age of onset of alcoholism related behaviors

The purpose of this study was to explore the association of a tryptophan hydroxylase gene polymorphism (TPHI A218C) with the age of alcoholism onset in a Korean population. The genotype and allele frequencies of TPHI were investigated in 182 male hospitalized patients who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-fV-TR) criteria for alcohol dependence. Alcoholics with the TPHI AA or AC genotypes had an earlier age of disease onset (median age of onset, 26.5 years) than those with the CC genotype (median age of onset, 30 years; p = .002). Age of onset has been used in classifying alcoholics. The TPHI polymorphism may explain, in part, the biological basis for these typologies. (c) 2005 Elsevier Inc. All rights reserved.