title: No Evidence for an Association between Dopamine D2 Receptor Polymorphisms and Tardive Dyskinesia in Korean Schizophrenia Patients.
abstract: OBJECTIVE
  Tardive dyskinesia (TD) is a long-term adverse effect of antipsychotic. Dopaminergic activity in the nigrostriatal system have been proposed to be involved in development of TD and dopamine D2 receptors (DRD2) has been regarded as a candidate gene for TD because the antipsychotics have potent antagonism DRD2. This study was aimed to find the relationship between DRD2 gene and antipsychotic-induced TD.
  
  
  METHODS
  We evaluated whether 5 DRD2 single nucleotide polymorphisms (-141Cins>del/TaqID/NcoI/Ser311Cys/TaqIA) are associated with antipsychotic-induced TD in 263 Korean schizophrenia patients with (n=100) and without TD (n=163) who were matched for antipsychotic drug exposure and other relevant variables. Haplotype analyses were also performed.
  
  
  RESULTS
  None of 5 polymorphisms were found to be significantly associated with TD and with TD severity as measured by Abnormal Involuntary Movement Scale. Overall haplotype (-141Cins>del/TaqID/NcoI/Ser311Cys/TaqIA) frequency was also not significantly different between TD and non-TD groups, although one rare haplotype (I-D1-T-G-A1) showed significantly different frequency between TD and non-TD groups (2.7% vs. 8.5%, respectively, p=0.031).
  
  
  CONCLUSIONS
  The present study does not support that DRD2 gene may be involved in TD in the Korean population, although further studies are warranted.
authors.affiliation: Department of Psychiatry, Inje University College of Medicine, Goyang, Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Park
authors.forename: Seung-Gul
authors.initials: SG
authors.lastname: Kang
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Choi
authors.forename: Yong-Ku
authors.initials: YK
authors.lastname: Kim
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Park
authors.forename: Leen
authors.initials: L
authors.lastname: Kim
authors.forename: Heon-Jeong
authors.initials: HJ
authors.lastname: Lee