title: Allelic association between a Ser-9-Gly polymorphism in the dopamine D3 receptor gene and schizophrenia.
abstract: We examined a Ser-9-Gly polymorphism in the dopamine D3 receptor gene for allelic association with schizophrenia in 133 patients currently treated with clozapine and 109 controls. Allele 1 (Ser-9) was significantly more frequent in the patients (69%) than in the controls (56%) (P = 0.004). The 1-1 genotype was more common (43% vs 30%) and the 2-2 genotype less common (5% vs 18%) in patients than in controls. When the patient group was subdivided on the basis of clinical response to clozapine, using a 20-point improvement in the global assessment scale as cut-off, genotype 1-1 was found to be more frequent among the non-responders (53% vs 36%, P = 0.04). To place our results in the context of previous studies of this polymorphism and schizophrenia, we performed a meta-analysis of all published data including the present sample. The combined analysis shows evidence for a modest association between genotype 1-1 and schizophrenia (odds ratio 1.25, 95% confidence interval 1.05-1.49, P = 0.01). These results suggest that the Ser-9 allele, or a nearby polymorphism in linkage disequilibrium, results in a small increase in susceptibility to schizophrenia.
authors.affiliation: Department of Psychological Medicine, Institute of Psychiatry, Denmark Hill, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Shaikh
authors.forename: D A
authors.initials: DA
authors.lastname: Collier
authors.forename: P C
authors.initials: PC
authors.lastname: Sham
authors.forename: D
authors.initials: D
authors.lastname: Ball
authors.forename: K
authors.initials: K
authors.lastname: Aitchison
authors.forename: H
authors.initials: H
authors.lastname: Vallada
authors.forename: I
authors.initials: I
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Gill
authors.forename: R W
authors.initials: RW
authors.lastname: Kerwin
mesh_terms: D000483:Alleles; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001483:Base Sequence; D003024:Clozapine / Q000627:therapeutic use; D004198:Disease Susceptibility; D018628:Gene Dosage; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050637:Receptors, Dopamine D3; D012559:Schizophrenia / Q000188:drug therapy / Q000208:ethnology / Q000235:genetics*
chemical_list: D014150:Antipsychotic Agents; C493593:DRD3 protein, human; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D003024:Clozapine