(A) Pairwise analyses of the top signal for each of volume, surface area, and thickness from the discovery cohort determined that aggregate effects were attributable to individual ROIs (and see S5 Table). Post-hoc permutation testing, accounting for all 52 tag-SNPs and ROIs examined, found a significant association between rs4778298 genotype and the surface area of the left supramarginal gyrus (lh.SMG) in Caucasian subjects (ppermutation corrected = 7.5x10-3). (B) Linear effects at the CC and lh.SMG were observed for rs12102024 and rs4778298, respectively, consistent with an effect of allele dosage. rh.ACC and CC correspond to right anterior cingulate cortex and corpus callosum, respectively.