Case-control, haplotype relative risk and transmission disequilibrium analysis of a dopamine D2 receptor functional promoter polymorphism in schizophrenia.

Abstract

The dopamine system has long been suspected of aetiological involvement in schizophrenia because of a number of lines of evidence pointing to excess dopaminergic activity in the illness. Recently, negative allelic association was reported between a single base deletion in the promoter region of the DRD2 gene, -141 delta C, and schizophrenia, with an odds ratio of 0.60. This was of particular interest since the deletion, which occurs in about 22% of the Japanese population, is functional in that it results in reduced (20-40% of wild-type) basal levels of receptor expression. We have examined this polymorphism in 229 family trios from SW China, consisting of both parents and a single offspring..