title: Glutamate system genes and brain volume alterations in pediatric obsessive-compulsive disorder: a preliminary study.
abstract: Obsessive-compulsive disorder (OCD) has been associated with regional volumetric brain abnormalities, which provide promising intermediate phenotypes of the disorder. In this study, volumes of brain regions selected for a priori evidence of association with OCD (orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), thalamus, caudate, putamen, globus pallidus and pituitary) were measured using structural magnetic resonance imaging (MRI) in 20 psychotropic-naïve pediatric OCD patients. We examined the association between these regional brain volumes and a total of 519 single nucleotide polymorphisms (SNPs) from nine glutamatergic candidate genes (DLGAP1, DLGAP2, DLGAP3, GRIN2B, SLC1A1, GRIK2, GRIK3, SLITRK1 and SLITRK5). These genes were selected based on either previous reported association with OCD in humans or evidence from animal models of OCD. After correcting for multiple comparisons by permutation testing, no SNP remained significantly associated with volumetric changes. The strongest trend toward association was identified between two SNPs in DLGAP2 (rs6558484 and rs7014992) and OFC white matter volume. Our other top ranked association findings were with ACC, OFC and thalamus. These preliminary results suggest that sequence variants in glutamate candidate genes may be associated with structural neuroimaging phenotypes of OCD.
authors.affiliation: Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8.
authors.forename: Ke
authors.initials: K
authors.lastname: Wu
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Hanna
authors.forename: Philip
authors.initials: P
authors.lastname: Easter
authors.forename: James L
authors.initials: JL
authors.lastname: Kennedy
authors.forename: David R
authors.initials: DR
authors.lastname: Rosenberg
authors.forename: Paul D
authors.initials: PD
authors.lastname: Arnold
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology*; D002648:Child; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D018698:Glutamic Acid / Q000235:genetics*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics; D009771:Obsessive-Compulsive Disorder / Q000235:genetics* / Q000473:pathology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: C413124:DLGAP2 protein, human; D009419:Nerve Tissue Proteins; D018698:Glutamic Acid