Korean Journal of Biological Psychiatry

The finding of contrasting results regarding an association between schizophrenia and the MluI polymorphism site in the dopamine D₃ receptor gene prompted us to study the distribution of this polymorphism in Korean schizophrenic patients and controls. The author;s approach was case-control study. Schizophrenic patients(n=66) and controls(n=76) were examined by case-control study for distribution of the MluI polymorphism of the dopamine D₃ receptor gene in Korean population to minimize the effect of racial differencies in gene frequencies. The frequency of the allele 1 in Schizophrenic patients and controls was 0.66 and 0.76, respectively. There was no significant differencies in the frequency of the allele 1 between schizophrenic pateitns and controls(x²=3.07, p>.05), and between positive and negative schizophrenic patients(x²=1.02, p>.05). We present here the evidence of a loack of alleic association between the MluI polymorphism of the dopamine D₃ receptor gene and Korean schizophrenic patients and also report no increased homozygosity for the MluI polymorphism. The assumption that the dopamine D₃ receptor gene has a predisposing role in schizophrenia was not supported by this case-control study. Although, the possibility that this gene has a minor gene effects in the etiology of schizophrenia cannot be excluded because of the intrinsic limitations of the methods of analysis and number of subjects in our study.

Keywords Schizophrenia;Case-control study;Dopamine D₃ receptor;Association.