ABSTRACT
OBJECTIVE: Catechol-O-methyltransferase(COMT) is an important enzyme that inactivates biologically active or toxic catechols. Abnormal catecholamine transmission has been implicated in the pathogenesis of schizophrenia and bipolar disorder. Polymorphism(Val/Met) of the COMT gene was shown to determine high-and low-activity alleles of the enzyme. This study was designed to investigate the association between COMT gene polymorphism and schizophrenia and bipolar disorder in a Korean population. METHOD: COMT gene were genotyped with polymerase chain reaction and restriction enzyme NlaIII in 128 patients with schizophrenia, 110 with bipolar disorder, and 176 controls. RESULTS: 1) The distribution of the COMT genotype in schizophrenic patients with Val/Val, Val/Met, Met/Met were 76(59.4%), 43(33.6%), 9(7.0%), in bipolar disorder patients were 63(57.3%), 35(31.8%), 12(10.9%), and in the controls were 83(47.2%), 79(44.9%), 14(8.0%). The allele frequencies of the COMT gene in schizophrenic patients with Val and Met were 195(76.2%), 61(23.8%), in bipolar disoreder patients were 161(73.2%), 59(26.8%), and in the controls were 245(69.6%), 107(30.4%). 2) There were no differences in genotype distribution and allele frequencies of COMT gene polymorphism among the 3 groups. Neither patients with schizophrenia nor bipolar disorder differed in the genotype and allelic frequencies from the controls. CONCLUSION: These results suggest COMT gene polymorphism is not causally related to the development of schizophrenia and bipolar disorder in a Korean Population.