title: Dopamine D3 receptor gene Ser9Gly variant and schizophrenia: association study and meta-analysis.
abstract: OBJECTIVE
  To further evaluate the controversial putative association between a Ser9Gly variant in the first exon of the dopamine D3 receptor gene (DRD3) and schizophrenia.
  
  
  METHODS
  Swedish patients with schizophrenia ( n=156) and control subjects ( n=463) were assessed for the DRD3 Ser9Gly variant. Meta-analyses including previous and the present Swedish case-control results were performed.
  
  
  RESULTS
  No significant difference between the Swedish patients and controls were found, but there was an association between DRD3 Ser9Gly Ser/Ser and homozygous genotypes and response to anti-psychotic drugs. This finding was supported by an incomplete meta-analysis. In a meta-analysis of all case-control studies comprising 8761 subjects the association between DRD3 Ser9Gly homozygosity and schizophrenia ( =4.96, degree of freedom=1, p <0.05, odds ratio=1.10, 95% confidence interval=1.01-1.20) persisted. However, the previously proposed association between the Ser/Ser genotype and schizophrenia was not significant (chi2 =2.71, degree of freedom=1, p>0.05, odds ratio=1.08, 95% confidence interval=0.99-1.17).
  
  
  CONCLUSIONS
  Whereas the present Swedish case-control analysis did not yield any evidence for association with the diagnosis, the present meta-analysis suggests that the DRD3 gene confer susceptibility to schizophrenia. Reasons for the discrepancies between prior studies are discussed.
authors.affiliation: Department of Clinical Neuroscience, HUBIN Project, Karolinska Institutet, Stockholm, Sweden. erikj@ks.se
authors.forename: Erik G
authors.initials: EG
authors.lastname: Jönsson
authors.forename: Lena
authors.initials: L
authors.lastname: Flyckt
authors.forename: Edgar
authors.initials: E
authors.lastname: Burgert
authors.forename: Marc-Antoine
authors.initials: MA
authors.lastname: Crocq
authors.forename: Kaj
authors.initials: K
authors.lastname: Forslund
authors.forename: Marja
authors.initials: M
authors.lastname: Mattila-Evenden
authors.forename: Gunnar
authors.initials: G
authors.lastname: Rylander
authors.forename: Marie
authors.initials: M
authors.lastname: Asberg
authors.forename: Vishwajit L
authors.initials: VL
authors.lastname: Nimgaonkar
authors.forename: Gunnar
authors.initials: G
authors.lastname: Edman
authors.forename: Lars
authors.initials: L
authors.lastname: Bjerkenstedt
authors.forename: Frits-Axel
authors.initials: FA
authors.lastname: Wiesel
authors.forename: Göran C
authors.initials: GC
authors.lastname: Sedvall
mesh_terms: D019943:Amino Acid Substitution; D016022:Case-Control Studies; D014644:Genetic Variation; D005998:Glycine; D006720:Homozygote; D006801:Humans; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050637:Receptors, Dopamine D3; D012016:Reference Values; D012559:Schizophrenia / Q000235:genetics*; D012694:Serine; D013548:Sweden
chemical_list: C493593:DRD3 protein, human; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D012694:Serine; D005998:Glycine