We examined the expression of chr4p12 GABAA genes in a set of 60 adult post-mortem Caucasian brain samples using a whole genome microarray gene expression dataset [http://braincloud.jhmi.edu; (Colantuoni et al., 2011)], merged with SNP array data for each sample (dbGap dataset phs000417.v2.c1). Because rs279858 was not available in the SNP dataset for these samples, we examined 4p12 GABAA gene expression as a function of the GABRA2 intron 4 SNP, rs279856 located 3.3 kb from rs279858 and in near-complete linkage disequilibrium with it (r2=0.91) in Caucasians. There was no significant relationship of rs279856 genotype with GABRA2 RNA expression (F=0.67, df=2,57, p=0.52). Similar results were obtained examining expression data for a collection of post-mortem adult brain samples from 134 subjects of European descent [http://braineac.org/; UK Brain Expression Consortium, (Trabzuni et al., 2011)]. There was no association of rs279858 genotype with GABRA2 RNA expression in either frontal cortex (F=0.43, df=2,124, p=0.65) or hippocampus (F=1.25, df=2,119, p=0.29).
