We identified a number of genomic regions which contained multiple gene associations and/or genes associated across multiple tissues. We identified 58 of these regions, excluding the MHC, based on distance between associated genes, and verified them using visual inspection. In order to identify independent genic associations within these regions, we carried out a stepwise forward conditional analysis following “GCTA-COJO” theory85 using “CoCo” (see URLs), an R implementation of GCTA-COJO. CoCo allows the specification of custom correlation matrices by the user (for example, ancestrally specific LD matrices). For each region, we generated a predicted gene expression correlation matrix for all significant genes (p≤ 1×10−6), as the root-effective sample size83 (Neff, eqn 2) weighted average correlation across all cohorts where we had access to dosage data.
