title: Dopamine D2 receptor gene variants and quantitative measures of positive and negative symptom response following clozapine treatment.
abstract: OBJECTIVE
  Explore relationships between 12 dopamine D2 gene variants and quantitative measures of positive and negative symptom response following clozapine treatment in two treatment refractory or intolerant populations (Caucasian and African-American).
  
  
  METHODS
  Subjects included 97 Caucasian and 35 African-American DSM-III-R or DSM-IV schizophrenics and were genotyped by 5'-exonuclease fluorescence assays. Genotype, allele +/- and haplotype groups were compared on Brief Psychiatric Rating Scale (BPRS) overall, positive (BPOS) and negative symptom subscales (BNEG) using analysis of variance.
  
  
  RESULTS
  In Caucasians, no significant associations were found for any individual polymorphisms or haplotypes. In African-Americans, the TaqIB B2 (T) allele and rs1125394 allele 1 (A), and a two-marker haplotype containing these two alleles were associated with improvement in overall BPRS and BPOS response.
  
  
  CONCLUSIONS
  Variability in clozapine response is still not fully understood and likely involves multiple factors. This study suggests that D2 receptor gene variants may be among such factors.
authors.affiliation: Neurogenetics Section, Centre for Addiction and Mental Health, University of Toronto, 250 College Street, Toronto, Ontario M5T 1R8, Canada.
authors.forename: Rudi
authors.initials: R
authors.lastname: Hwang
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shinkai
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Deluca
authors.forename: Fabio
authors.initials: F
authors.lastname: Macciardi
authors.forename: Steven
authors.initials: S
authors.lastname: Potkin
authors.forename: Herbert Y
authors.initials: HY
authors.lastname: Meltzer
authors.forename: James L
authors.initials: JL
authors.lastname: Kennedy
mesh_terms: D000328:Adult; D001741:Black or African American; D000483:Alleles; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D003024:Clozapine / Q000627:therapeutic use*; D003710:Demography; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D011569:Psychiatric Status Rating Scales; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D012559:Schizophrenia / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology; D016896:Treatment Outcome; D044465:White People
chemical_list: D014150:Antipsychotic Agents; D017448:Receptors, Dopamine D2; D003024:Clozapine