title: Association study between schizophrenia and dopamine D3 receptor gene polymorphism.
abstract: Crocq et al. [1992: J Med Genet 29:858-860] reported the existence of an association between schizophrenia and homozygosity of a BalI polymorphism in the first exon of the dopamine D3 receptor (DRD3) gene. In response to this report, further studies were conducted; however, these studies yielded conflicting results. In the present study, we examined 100 unrelated Japanese schizophrenics and 100 normal controls to determine any association between this polymorphism and schizophrenia. Results suggest that neither allele nor genotype frequencies of the DRD3 gene in the schizophrenics as a whole are significantly different from those of the controls. Further, we found no association between any allele or genotype and any clinical subtype based on family history of schizophrenia and age-at-onset. A significantly high frequency of homozygosity of a dopamine D3 receptor gene allele was not observed in the schizophrenics as a whole, or in clinical subtypes. Our results suggest that an association between the dopamine D3 receptor gene and schizophrenia is unlikely to exist.
authors.affiliation: Department of Psychiatry, Niigata University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Igarashi
authors.forename: O
authors.initials: O
authors.lastname: Onodera
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Maeda
authors.forename: K
authors.initials: K
authors.lastname: Kameda
authors.forename: S
authors.initials: S
authors.lastname: Tsuji
authors.forename: S
authors.initials: S
authors.lastname: Ihda
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000483:Alleles; D015252:Deoxyribonucleases, Type II Site-Specific; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050637:Receptors, Dopamine D3; D012559:Schizophrenia / Q000235:genetics*
chemical_list: C493593:DRD3 protein, human; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D015252:Deoxyribonucleases, Type II Site-Specific; C060616:TGGCCA-specific type II deoxyribonucleases