Dopamine D2 receptor gene polymorphisms and clinical response to selective dopamine receptor antagonists

The subjects with A1 allele of TaqI A polymorphism of dopamine D-2 receptor (DRD2) gene and those without Del allele of - 141C Ins/Del polymorphism in the promoter region of DRD2 gene have lower DRD2 density in the brain. The present study reviewed the relationship between two DRD2 gene polymorphisms and clinical response to selective dopamine antagonists mainly in schizophrenic patients. The patients with A1 allele showed higher percentage improvement in total and positive symptoms than those with no A1 allele when treated with nemonapride at 18 mg/day for 3 weeks. Greater improvement in anxiety-depression symptoms was observed in the patients without Del allele than in those with Del allele when treated with nemonapride at 18 mg/day and bromperidol at 6, 12, 18 mg/day for 3 weeks. Females with A1 allele showed greater prolactin responses to both drugs than those with no A I allele and males. The proportion of the A I carrier was higher in a group with a past history of neuroleptic malignant syndrome than in a control group. These findings suggest that two DRD2 gene polymorphisms can be used as biological makers in prediction of clinical response to selective dopamine antagonists. (C) 2002 Elsevier Science B.V. All rights reserved.