We next explored the extent to which cis-eQTL identified in the fetal brain are shared among 48 adult human tissues analyzed through the Genotype-Tissue Expression (GTEx) project [4]. For this, we restricted our analyses to the eQTL we identified for fetal eGenes as the GTEx project does not currently provide eQTL data at the individual transcript level. Of the 1151 fetal brain eGenes for which GTEx Consortium data were available, 979 had a top eQTL (the most significant fetal brain eQTL for that gene that was genotyped in the GTEx study) that was also observed in at least one adult tissue (at FDR < 0.05). The shared eQTL for 974 of these fetal eGenes were predicted to be active in at least two adult tissues. Tissue-sharing of fetal brain eQTL was most pronounced within regions of the adult brain, where 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
