Estimating the causal tissues for complex traits and diseases

Interpretation of biological causes of the predisposing markers identified through Genome Wide Association Studies (GWAS) remains an open question1. One direct and powerful way to assess the genetic causality behind GWAS is through expression quantitative trait loci (eQTLs)2. Here we describe a novel approach to estimate the tissues giving rise to the genetic causality behind a wide variety of GWAS traits, using the cis-eQTLs identified in 44 tissues of the GTEx consortium3,4. We have adapted the Regulatory Trait Concordance (RTC) score5, to on the one hand measure the tissue sharing probabilities of eQTLs, and also to calculate the probability that a GWAS and an eQTL variant tag the same un