Genetic association analysis between CYP2D6*2 allele and tardive dyskinesia in schizophrenic patients

Previous studies have shown a possible association between tardive dyskines ia (TD) and debrisoquine 4-hydroxylase (CYP2D6) polymorphisms, which result in absent enzyme activity. We have recently found a positive association b etween TD and the CYP2D6*10 allele, which codes for the intermediate metabo lizer (IM) phenotype and is characterized by decreased but not absent CYP2D 6 activity in Japanese schizophrenic patients. In addition, the CYP2D6*2 al lele with the HhaI site mutation in exon 6 has also been reported to be an IM allele and a risk factor for Parkinson's disease (PD) in the Japanese po pulation. In the present study, we investigated potential contributions of the CYP2D6*2 allele to TD using case-control and regression analysis in 99 schizophrenic patients. No significant differences in genotypic and allelic frequencies were found between patients with and without TD. Even after us ing regression analysis to adjust for the confounding variables, there was no significant association of the CYP2D6*2 genotype with either outcome var iable, the occurrence of TD or the total AIMS score. These results suggest that the CYP2D6*2 allele may not contribute to the pathogenesis of TD. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.