A case-control study of the relationship between the metabotropic glutamate receptor 3 gene and schizophrenia in the Chinese population.

Recent studies of the association between the metabotropic glutamate receptor 3 gene (GRM3) and schizophrenia have produced conflicting results, although GRM3 is a promising candidate gene. Fujii et al. found a single nuclear polymorphism (SNP) for within this gene, rs1468412 to have a positive association to schizophrenia in Japanese patients. To investigate this further, we genotyped 7 SNPs around GRM3 including rs1468412, in 752 Chinese patients with schizophrenia and 752 controls using Taqman technology. We did not detect any association between rs1468412 and schizophrenia, however we found differences in the allele frequency distribution of SNP rs2299225 (p=0.0297, odds ration [OR]=1.44, 95% confidence interval 1.05-1.99) between cases and controls. Moreover, the overall frequency of haplotypes constructed from three SNPs including rs2299225 showed significant differences between cases and controls (p=0.0017). Our results partially support the previous studies in other ethnic groups and indicate that the GRM3 gene may play an important role in the etiology of schizophrenia in the Han Chinese.