Glutamate AMPA receptor subunit 1 gene (GRIA1) and DSM-IV-TR schizophrenia: a pilot case-control association study in an Italian sample.

Glutamatergic dysfunction is one of the major hypotheses for the pathogenesis of schizophrenia. The GRIA1 gene encodes for one (GluR1) of the four (GluR1-4) ionotropic AMPA receptor subunits. GRIA1 is a good candidate gene for susceptibility to schizophrenia since it maps in 5q33, a region where the presence of susceptibility loci has been suggested by independent genome-wide scans and because its expression has been found to be decreased in the brain of some schizophrenia patients. We present data from a case-control association study on the Italian population with eight polymorphisms spanning the whole GRIA1 gene. Single-locus analysis revealed a significantly different allele distribution in cases and in controls of two SNPs (rs707176, 0.41 vs. 0.31, P = 0.009; rs2963944, 0.41 vs. 0.30, P = 0.007), and one microsatellite (rs10631988, allele 9: 0.40 vs. 0.29, P = 0.004). Haplotype analysis showed an increased frequency of a specific haplotype for these markers (C09CC, 0.39 vs. 0.28, P = 0.009). Therefore our data indicate that GRIA1 may be involved in susceptibility to DSM-IV-TR schizophrenia.