an average of 79% of the tested fetal brain eQTL were predicted to be shared, and lowest for whole blood, where only 41% of the tested fetal brain eQTL were predicted to be shared (Fig. 2). Predicted tissue sharing was supported by estimates of π1 (the proportion of true positives [30]) among fetal eQTL when tested for replication in individual GTEx tissues, with high π1 estimates in adult brain regions despite relatively small GTEx sample sizes (Additional file 2: Figure S4). For 172 eGenes assayed by the GTEx Consortium, the eQTL identified in fetal brain were not associated with significant (FDR < 0.05) effects on their expression in any sampled adult tissue, and these might therefore constitute fetal-specific eQTL (Additional file 1: Table S6).
