C957T DRD2 polymorphism is associated with schizophrenia in Spanish patients.

Objective: The objective was to confirm whether a homozygous genotype for the C957 allele of the C957T DRD2 gene single nucleotide polymorphism (SNP) is associated with schizophrenia in an independent study population. Method: We examined the genotypic distribution of this SNP in a set of clinically ascertained schizophrenic patients ( n = 131) and age-matched control subjects ( n = 364). Individuals were genotyped using automated analysis of fluorescently labeled PCR products. Results: The distribution of grouped genotypes for the C957T DRD2 SNP (CC vs. CT, TT) showed that C homozygote genotype was over-represented in our patient sample when compared with control subjects. This difference reaches the statistical significance ( χ² = 7.0; df = 1; P = 0.008; OR = 2.05; % CI 1.2–3.4). Conclusion: The findings of this study provide additional evidence that genetic variation at the DRD2 gene plays an important role in the vulnerability to schizophrenia. [ABSTRACT FROM AUTHOR]