title: Cytochrome P450 II D6 gene polymorphisms and the neuroleptic-induced extrapyramidal symptoms in Japanese schizophrenic patients.
abstract: OBJECTIVE
  The purpose of this study was to examine whether the neuroleptic-induced extrapyramidal symptoms are associated with the CYP2D6 activity.
  
  
  METHODS
  The CYP2D6 gene polymorphisms (CYP2D6*2, CYP2D6*3, CYP2D6*4, CYP2D6*10, and CYP2D6*12) were genotyped in 196 normal controls and 320 schizophrenic patients receiving neuroleptics. The relationships with susceptibility to extrapyramidal symptoms (EPS) and tardive dyskinesia, and with steady-state serum haloperidol levels in maintenance therapy, were investigated.
  
  
  RESULTS
  The allele frequency of CYP2D6*2 was significantly higher, while that of CYP2D6*10 tended to be higher in the schizophrenic patients susceptible to acute EPS. The steady-state serum haloperidol levels per daily dosage were observed to be significantly higher in schizophrenic patients with the mutant-type homozygote of CYP2D6*2, while this difference was trend level in those of CYP2D6*10. However, no significant difference was observed in the distribution of both CYP2D6*2 (C2938T) and CYP2D6*10 (C188T) polymorphisms between schizophrenic patients with or without tardive dyskinesia.
  
  
  CONCLUSIONS
  The present results suggest that the homozygotes of CYP2D6*2 and CYP2D6*10 appear to be a susceptibility factor for developing acute EPS in schizophrenic patients and for impaired neuroleptic metabolism in Japanese schizophrenic patients.
authors.affiliation: National Institute of Mental Health, National Center of Neurology and Psychiatry, Chiba, Japan. inada@med.nagoya-u.ac.jp
authors.forename: Toshiya
authors.initials: T
authors.lastname: Inada
authors.forename: Hisashi
authors.initials: H
authors.lastname: Senoo
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Iijima
authors.forename: Tadamitsu
authors.initials: T
authors.lastname: Yamauchi
authors.forename: Gohei
authors.initials: G
authors.lastname: Yagi
mesh_terms: D014150:Antipsychotic Agents / Q000009:adverse effects*; D001480:Basal Ganglia Diseases / Q000139:chemically induced / Q000235:genetics*; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006720:Homozygote; D006801:Humans; D007564:Japan; D011110:Polymorphism, Genetic / Q000235:genetics*; D012016:Reference Values; D012559:Schizophrenia / Q000201:enzymology / Q000235:genetics*
chemical_list: D014150:Antipsychotic Agents; D019389:Cytochrome P-450 CYP2D6