RT Journal Article SR Electronic T1 Integrative approaches for large-scale transcriptome-wide association studies JF bioRxiv FD Cold Spring Harbor Laboratory SP 024083 DO 10.1101/024083 A1 Alexander Gusev A1 Arthur Ko A1 Huwenbo Shi A1 Gaurav Bhatia A1 Wonil Chung A1 Brenda W J H Penninx A1 Rick Jansen A1 Eco JC de Geus A1 Dorret I Boomsma A1 Fred A Wright A1 Patrick F Sullivan A1 Elina Nikkola A1 Marcus Alvarez A1 Mete Civelek A1 Aldonis J Lusis A1 Terho Lehtimäki A1 Emma Raitoharju A1 Mika Kähönen A1 Ilkka Seppälä A1 Olli T. Raitakari A1 Johanna Kuusisto A1 Markku Laakso A1 Alkes L. Price A1 Päivi Pajukanta A1 Bogdan Pasaniuc YR 2015 UL http://biorxiv.org/content/early/2015/08/07/024083.1.abstract AB Many genetic variants influence complex traits by modulating gene expression, thus altering the abundance levels of one or multiple proteins. In this work we introduce a powerful strategy that integrates gene expression measurements with large-scale genome-wide association data to identify genes whose cis-regulated expression is associated to complex traits. We use a relatively small reference panel of individuals for which both genetic variation and gene expression have been measured to impute gene expression into large cohorts of individuals and identify expression-trait associations. We extend our methods to allow for indirect imputation of the expression-trait association from summary association statistics of large-scale GWAS1-3. We applied our approaches to expression data from blood and adipose tissue measured in ∼3,000 individuals overall. We then imputed gene expression into GWAS data from over 900,000 phenotype measurements4-6 to identify 69 novel genes significantly associated to obesity-related traits (BMI, lipids, and height). Many of the novel genes were associated with relevant phenotypes in the Hybrid Mouse Diversity Panel. Overall our results showcase the power of integrating genotype, gene expression and phenotype to gain insights into the genetic basis of complex traits.