Genetic association between the dopamine D3 receptor gene polymorphism (Ser9Gly) and tardive dyskinesia in patients with schizophrenia: A reevaluation in East Asian populations

Abstract

The dopamine D3 receptor gene ( DRD3) is considered being one of the candidate genes contributing to the development of tardive dyskinesia (TD). In a recent meta-analysis with mixed ethnicities, only a barely positive association was found between the functional DRD3 Ser9Gly polymorphism and TD in patients with schizophrenia (OR = 1.17; 95% CI: 1.01–1.37; p = 0.041). To further evaluate the controversial association between the polymorphism and TD using only Japanese subjects, we tested the association in a case-control design. We also conducted a meta-analysis including 8 studies with 3 East Asian populations (Japanese, Chinese, and Korean). In our Japanese case-control sample (43 with TD/157 without TD), we found no association between the DRD3 Ser9Gly polymorphism in schizophrenia and TD (genotype: p = 0.92; allele: p = 1.00). Furthermore, no significant difference in the mean AIMS score among the three genotypic groups was observed in our sample. The meta-analysis comprising 1291 East Asian subjects also showed no association between the polymorphism and TD; the Mantel–Haenszel pooled OR for TD among carriers of the DRD3 Ser9Gly of the eight Asian studies was 0.94 (95% CI: 0.78–1.12). Overall, our results suggest that the DRD3 Ser9Gly polymorphism may not confer susceptibility to TD in East Asian populations. Given that the Ser9Gly variant may play a putative role in the DRD3 function, further studies on the DRD3 are warranted.