Glutamate System Genes Associated with Ventral Prefrontal and Thalamic Volume in Pediatric Obsessive-Compulsive Disorder

This pilot study was undertaken to determine if there was a significant association between specific glutamate system genes and regional volumes of interest implicated in the pathogenesis of obsessive-compulsive disorder (OCD). Volumetric magnetic resonance imaging (MRI) and genotyping of seven polymorphisms in two genes, glutamate receptor, ionotropic, N-methyl-d-aspartate 2B (GRIN2B) and solute linked carrier, family 1, member 1 (SLC1A1) were conducted in 31 psychotropic-naive pediatric OCD patients. The rs1805476 variant of GRIN2B was associated with left but not right orbital frontal cortex (OFC) (p=0.04) and right but not left anterior cingulate cortex (ACC) volume (p=0.02). The SLC1A1 rs3056 variant was associated with increased total (p=0.01), left (p=0.02) and right (p=0.02) thalamic volume. These results suggest that GRIN2B and SLC1A1 may be associated with regional volumetric alterations in OFC, ACC, and thalamus in children with OCD.