No association between dopamine D4 receptor gene -521 C/T polymorphism and tardive dyskinesia in schizophrenia

Tardive dyskinesia (TD) is a long-term adverse effect of antipsychotics. We evaluated whether a candidate functional polymorphism of the dopamine D4 receptor (DRD4) gene is associated with drug-induced TD in 209 Korean schizophrenic patients with TD (n = 83) and without TD (n = 126) who were matched for antipsychotic drug exposure and other relevant variables. There was no significant association of the genotype and allele frequencies determined by the -521 C/T SNP of DRD4 between TD and non-TD patients. In addition, there was no significant difference in terms of total Abnormal Involuntary Movement Scale scores among the 3 genotype groups. Within the limitations imposed by the size of the clinical sample, these findings suggest that the DRD4 -521 C/T SNP does not contribute significantly to the risk for TD.