Korean Journal of Biological Psychiatry

Objects : Clozapone, prototype of the atypocal, was known to have unique antipsychitic effect with a few extrapyramidal effects. While most typical antipsychofic agents mainly block D₂ receptors, clozopine has higher affinity for dopamine D₄ receptor than for D₂ receptor. Many researchers have tried to find out the relationship between schizophrenia and the abnormality of the genes coding dopamine receptors. But no consistent findings were reported. Recently, dopamine D₄ receptor was fylly sequenced, and the alleles of dopamine D₄ receptor gene was found in unusual form on the 48th base pair. Our study was performed to identify the distribution of the dopamine D₄ receptor alleles of schizophrenics and normal controls, and whether any difference befference between the dopamine D₄ receptor alleles of schizophrenics and that of normal controls exists.

Methods : DNA was extracted from the blood of schizophrenic patients(N=60) and normal controls(N=60). Part of the dopamine D₄ receptor gene was amplilied by PCR, and amplified DNA was electrophoresed. Authors compared the distribution of the alleles of dopamine D₄ receptor gene of normal controls and that of schizophrenic patients. 

Results : Six kinds of alleles of D₄ receptor were observed both groups. The fouth repeat form of alleles was the most common in both schizophrenic potients(75.8%) and normal controls(70.3%), so there was not signilicant difference between two groups.

Conclusion : The difference in the distribution of the dopamine D₄ receptor gene alleles is not thought to be responsible for the pothophysiology of the schizophrenia. However, the difference in the expression of the dopamine D₄ receptor gene between normal and schizophrenia is lefi to be scrutinized.

Keywords Schizophrenia;Dopamine D₄ receptor;Alleles.