No Association of CYP2D6*4 and CYP2D6*10 Polymorphisms with Tardive Dyskinesia in Korean Schizophrenics

ABSTRACT

P450 CYP2D6 enzyme(debrisoquine hydroxylase) is known to metabolize many neuroleptics and some genetic polymorphisms in the CYP2D6 gene were reported to be associated with tardive dyskinesia(TD). We investigeted the association of two genetic polymorphisms in the CYP2D6 gene, CYP2D6*4 and CYP2D6*10, with TD in Korean schizophrenic subjects. Subjects consisted of 71 Korean schizophrenics and TD was evaluated using the Abnormal Involuntary Movement Scale(AIMS). There were no statistically significant differences in the demographic variables of age, male to female percentage and the current antipsychotic(CPZ equivalent) dose between the grup with TD and the group without TD. But the duration of antipsychotic drug exposure was siginificantly higher in the group without TD(p=0.000, by independent t-test). The mean AIMS score in the group with TD was 11.2+/-6.6(S.D.). Genotypings ofr the presence of CYP2D6*4 and CYP2D6*10 wee done using PCR amplifications and endonuclease digestions. There were no statistically significant genotypic and alleleic associations between TD and CYP2D6*4(by chi-square tests), and between TD and CYP2D6*10(by chi-square tests). These results indicate that the CYP2D6*4 and CYP2D6*10 polymorphisms have no significant roles in the causation of TD.