Identification of genetic variants in the neuronal form of tryptophan hydroxylase (TPH2)

Objective We screened the complete protein coding sequence of the newly identified neuronal form of tryptophan hydroxylase (TPH2) for genetic variants. Methods Genomic DNA samples from 24 African-Americans and 24 Caucasian-Americans in the Coriell human variation collection were screened by denaturing high-performance liquid chromatography followed by sequencing. Results We identified a number of genetic variants in both the coding and exon-flanking intronic sequences. Only one variant was identified that predicts a structural change in the TPH2 protein, and this was seen in only one out of 96 chromosomes. Conclusions The gene for TPH2 contains a number of polymorphisms that might serve as useful markers for association analyses of complex behavioral phenotypes or as actual risk factors. Structural polymorphisms are extremely rare in TPH2 and cannot therefore act as substantial risk factors for behavioral disorders in African-American and Caucasian populations. (C) 2004 Lippincott Williams Wilkins.