The Association between Tardive Dyskinesia Induced by Haloperidol and Polymorphisms in the Serotonin Transporter Gene and Catecholamine-OMethyltransferase Gene in Korean Schizophrenic Patients

The existence of a genetic predisposition to tardive dyskinesia (TD) in human has been suggested. The purpose of this study was to assess whether haloperidol induced extrapyramidal symptom (EPS) and TD are associated with the polymorphisms of the genes encoding for the catechol-o-methyltransferase and serotonin transporter in Korean schizophrenic patients. Male schizophrenic patients who underwent haloperidol treatment for more than 3 consecutive months were recruited as the subjects in two psychiatric hospitals. All of the patients were evaluated by the extrapyramidal symptom rating scale and abnormal involuntary movement scale. The incidence rate of TD patients with the COMTH/COMTH genotype was higher than those with the COMTH/COMTL and COMTL/COMTL types. There were statistically significant differences with respect to the effect of the 5-HTTLPR genotype on the incidence rate of patients with EPS. The COMTL allele played a more significant role in the incidence of TD than the 5-HTTPR L allele. According to our results, COMT was associated with the incidence of TD while 5-HTTLPR was associated with the incidence of EPS in the schizophrenic patients treated with haloperidol.