RT Journal Article SR Electronic T1 Estimating the causal tissues for complex traits and diseases JF bioRxiv FD Cold Spring Harbor Laboratory SP 074682 DO 10.1101/074682 A1 Halit Ongen A1 Andrew A. Brown A1 Olivier Delaneau A1 Nikolaos Panousis A1 Alexandra C. Nica A1 GTEx Consortium A1 Emmanouil T. Dermitzakis YR 2016 UL http://biorxiv.org/content/early/2016/09/11/074682.abstract AB 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 underlying functional effect. We show that our tissue sharing estimates significantly correlate with commonly used estimates of tissue sharing. By normalizing the GWAS-eQTL probabilities with the tissue sharing estimates of the eQTLs, we can estimate the tissues from which GWAS genetic causality arises. Our approach not only indicates the gene mediating individual GWAS signals, but also can highlight tissues where the genetic causality for an individual trait is manifested.