Role of metabotropic glutamate receptor 7 in autism spectrum disorders: a pilot study

The presence of genetic variants for autism spectrum disorders (ASDs) was investigated for the metabotropic glutamate receptor 7 (GRM7) gene in a case-control study.

Employing Affymetrix SNP microarrays, 297 single nucleotide polymorphisms (SNPs) covering the GRM7 gene were selected and analyzed in ASD patients (n=22), non-ASD patients [n=14, including seven patients with development delay (DD)/mental retardation (MR), four patients with language delay (LD), and three patients with attention deficit hyperactivity disorder (ADHD)] and normal control subjects (n=18).

Twenty-one statistically significant SNPs with different inheritance models (recessive, dominant and allele) were demonstrated in three groups (ASDs vs. combined controls, ASDs vs. normal controls, ASDs vs. non-ASD patients). Associations of rs779867 and rs6782011 with ASDs were significant in all three groups and independent associations of rs779867 and rs6782011 with ASDs were found in the ASD vs. combined controls group, which are in modest linkage disequilibrium (D'>0.5). Further haplotype analysis showed that rs6782011/rs779867 (T-C) was statistically significantly related to ASDs in both the ASD vs. combined controls and ASD vs. normal controls groups (bootstrap P value=0.013, permutation P value=0.013 for the former group and bootstrap P value=0.002, permutation P value=0.020 for the latter).

These findings support a role for genetic variants within the GRM7 gene in 3p26.1 in ASDs.