Dopamine D1 receptor gene polymorphism and schizophrenia in Japan

We studied the relationship between schizophrenia and the DdeI polymorphism in the 5' untranslated region (5'UTR) of the dopamine D1 receptor (DRD1) g ene. This polymorphism is an A (Al allele) to G; (A2 allele) transition in the 5' UTR of exon 2 at bp -48 (A-48G). One hundred forty-eight schizophren ics and 148 control subjects were investigated. No significant differences in genotypic counts and allele frequencies between schizophrenics and contr ols were found. Although a significant difference between the patients clas sified as disorganized type and the controls was discovered both in genotyp ic counts and allele frequencies, neither association proved significant wh en a Bonferroni correction was used. Moreover, there were no differences in scores of main symptoms of schizophrenia based on the Manchester Scale bet ween patients with A1/A1 genotype and those with. A1/A2 genotype. These fin dings suggest that this gene may not be involved in the pathogenesis of sch izophrenia. (C) 1999 Wiley-Liss, Inc.