ASSOCIATION OF DOPAMINE D2 RECEPTOR MOLECULAR VARIANT WITH SCHIZOPHRENIA

We have examined a variant of the dopamine D2 receptor gene (Ser311--> Cys) in 156 Japanese schizophrenic patients and 300 controls. The alle le frequency of Cys311 was significantly higher in the whole patient g roup (0.054), among patients with onset before age 25 (0.090), and amo ng those with a family history (0.135) than in the controls (0.018). 3 patients were homozygous for Cys311. The patients with Cys311 showed significantly less severe thought disorder and negative symptoms of sc hizophrenia than those without Cys311. The Cys311 variant of the D2 re ceptor may be a genetic risk factor for some types of schizophrenia.