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  • Perspective
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Opportunities and challenges for transcriptome-wide association studies

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Abstract

Transcriptome-wide association studies (TWAS) integrate genome-wide association studies (GWAS) and gene expression datasets to identify gene–trait associations. In this Perspective, we explore properties of TWAS as a potential approach to prioritize causal genes at GWAS loci, by using simulations and case studies of literature-curated candidate causal genes for schizophrenia, low-density-lipoprotein cholesterol and Crohn’s disease. We explore risk loci where TWAS accurately prioritizes the likely causal gene as well as loci where TWAS prioritizes multiple genes, some likely to be non-causal, owing to sharing of expression quantitative trait loci (eQTL). TWAS is especially prone to spurious prioritization with expression data from non-trait-related tissues or cell types, owing to substantial cross-cell-type variation in expression levels and eQTL strengths. Nonetheless, TWAS prioritizes candidate causal genes more accurately than simple baselines. We suggest best practices for causal-gene prioritization with TWAS and discuss future opportunities for improvement. Our results showcase the strengths and limitations of using eQTL datasets to determine causal genes at GWAS loci.

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Fig. 1: TWAS, like GWAS, frequently has multiple significant associations per locus.
Fig. 2: Co-regulation strongly predicts TWAS hit strength at the SORT1 locus.
Fig. 3: Correlated predicted expression can cause non-causal hits even in the absence of correlated total expression.
Fig. 4: Sharing of GWAS variants between expression models can contribute to non-causal hits even without correlated predicted expression.
Fig. 5: Co-regulation scenarios in TWAS that may lead to non-causal hits, from least to most general.
Fig. 6: Most candidate causal genes drop out after switching to a tissue with a less clear mechanistic relationship to the trait, owing to a lack of sufficient expression or sufficiently heritable expression.

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References

  1. Gallagher, M. D. & Chen-Plotkin, A. S. The post-GWAS era: from association to function. Am. J. Hum. Genet. 102, 717–730 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Gamazon, E. R. et al. A gene-based association method for mapping traits using reference transcriptome data. Nat. Genet. 47, 1091–1098 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Gusev, A. et al. Integrative approaches for large-scale transcriptome-wide association studies. Nat. Genet. 48, 245–252 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Barbeira, A. N. et al. Exploring the phenotypic consequences of tissue specific gene expression variation inferred from GWAS summary statistics. Nat. Commun. 9, 1825 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  5. Zhu, Z. et al. Integration of summary data from GWAS and eQTL studies predicts complex trait gene targets. Nat. Genet. 48, 481–487 (2016).

    Article  CAS  PubMed  Google Scholar 

  6. Hauberg, M. E. et al. Large-scale identification of common trait and disease variants affecting gene expression. Am. J. Hum. Genet. 100, 885–894 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Pavlides, J. M. W. et al. Predicting gene targets from integrative analyses of summary data from GWAS and eQTL studies for 28 human complex traits. Genome Med. 8, 84 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  8. He, X. et al. Sherlock: detecting gene-disease associations by matching patterns of expression QTL and GWAS. Am. J. Hum. Genet. 92, 667–680 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Wallace, C. et al. Statistical colocalization of monocyte gene expression and genetic risk variants for type 1 diabetes. Hum. Mol. Genet. 21, 2815–2824 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Giambartolomei, C. et al. Bayesian test for colocalisation between pairs of genetic association studies using summary statistics. PLoS Genet. 10, e1004383 (2014).

    PubMed  PubMed Central  Google Scholar 

  11. Plagnol, V., Smyth, D. J., Todd, J. A. & Clayton, D. G. Statistical independence of the colocalized association signals for type 1 diabetes and RPS26 gene expression on chromosome 12q13. Biostatistics 10, 327–334 (2009).

    Article  PubMed  Google Scholar 

  12. Hormozdiari, F. et al. Colocalization of GWAS and eQTL signals detects target genes. Am. J. Hum. Genet. 99, 1245–1260 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  13. Wen, X., Pique-Regi, R. & Luca, F. Integrating molecular QTL data into genome-wide genetic association analysis: probabilistic assessment of enrichment and colocalization. PLoS Genet. 13, e1006646 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  14. Nica, A. C. et al. Candidate causal regulatory effects by integration of expression QTLs with complex trait genetic associations. PLoS Genet. 6, e1000895 (2010).

    Article  PubMed  PubMed Central  Google Scholar 

  15. Mancuso, N. et al. Integrating gene expression with summary association statistics to identify genes associated with 30 complex traits. Am. J. Hum. Genet. 100, 473–487 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Gusev, A. et al. Transcriptome-wide association study of schizophrenia and chromatin activity yields mechanistic disease insights. Nat. Genet. 50, 538–548 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Sekar, A. et al. Schizophrenia risk from complex variation of complement component 4. Nature 530, 177–183 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. GTEx Consortium et al. Genetic effects on gene expression across human tissues. Nature 550, 204–213 (2017).

    Article  PubMed Central  Google Scholar 

  19. Willer, C. J. et al. Discovery and refinement of loci associated with lipid levels. Nat. Genet. 45, 1274–1283 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Liu, J. Z. et al. Association analyses identify 38 susceptibility loci for inflammatory bowel disease and highlight shared genetic risk across populations. Nat. Genet. 47, 979–986 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Franzén, O. et al. Cardiometabolic risk loci share downstream cis- and trans-gene regulation across tissues and diseases. Science 353, 827–830 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  22. Musunuru, K. et al. From noncoding variant to phenotype via SORT1 at the 1p13 cholesterol locus. Nature 466, 714–719 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Grundberg, E. et al. Mapping cis- and trans-regulatory effects across multiple tissues in twins. Nat. Genet. 44, 1084–1089 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Mancuso, N. et al. Probabilistic fine-mapping of transcriptome-wide association studies. Nat. Genet. https://doi.org/10.1038/s41588-019-0367-1 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. de Leeuw, C. A., Neale, B. M., Heskes, T. & Posthuma, D. The statistical properties of gene-set analysis. Nat. Rev. Genet. 17, 353–364 (2016).

    Article  PubMed  Google Scholar 

  26. Liu, S. J. et al. CRISPRi-based genome-scale identification of functional long noncoding RNA loci in human cells. Science 355, aah7111 (2017).

    Article  PubMed  Google Scholar 

  27. Palazzo, A. F. & Lee, E. S. Non-coding RNA: what is functional and what is junk? Front. Genet. 6, 2 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  28. Luo, Y. et al. Exploring the genetic architecture of inflammatory bowel disease by whole-genome sequencing identifies association at ADCY7. Nat. Genet. 49, 186–192 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Finucane, H. K. et al. Heritability enrichment of specifically expressed genes identifies disease-relevant tissues and cell types. Nat. Genet. 50, 621–629 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Barbeira, A. N. et al. Integrating predicted transcriptome from multiple tissues improves association detection. PLoS Genet. 15, e1007889 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  31. Hu, Y. et al. A statistical framework for cross-tissue transcriptome-wide association analysis. Nat. Genet. 51, 568–576 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Xu, Z., Wu, C., Wei, P. & Pan, W. A powerful framework for integrating eQTL and GWAS summary data. Genetics 207, 893–902 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Wu, M. C. et al. Rare-variant association testing for sequencing data with the sequence kernel association test. Am. J. Hum. Genet. 89, 82–93 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Mogil, L. S. et al. Genetic architecture of gene expression traits across diverse populations. PLoS Genet. 14, e1007586 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  35. Võsa, U. et al. Unraveling the polygenic architecture of complex traits using blood eQTL meta-analysis. Preprint at https://www.biorxiv.org/content/10.1101/447367v1 (2018).

  36. Wheeler, H. E. et al. Imputed gene associations identify replicable trans-acting genes enriched in transcription pathways and complex traits. Preprint at https://www.biorxiv.org/content/10.1101/471748v1 (2018).

  37. Boyle, E. A., Li, Y. I. & Pritchard, J. K. An expanded view of complex traits: from polygenic to omnigenic. Cell 169, 1177–1186 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Engreitz, J. M. et al. Local regulation of gene expression by lncRNA promoters, transcription and splicing. Nature 539, 452–455 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Solovieff, N., Cotsapas, C., Lee, P. H., Purcell, S. M. & Smoller, J. W. Pleiotropy in complex traits: challenges and strategies. Nat. Rev. Genet. 14, 483–495 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Bhutani, K., Sarkar, A., Park, Y., Kellis, M. & Schork, N. J. Modeling prediction error improves power of transcriptome-wide association studies. Preprint at https://www.biorxiv.org/content/10.1101/108316v1 (2017).

  41. Ongen, H. et al. Estimating the causal tissues for complex traits and diseases. Nat. Genet. 49, 1676–1683 (2017).

    Article  CAS  PubMed  Google Scholar 

  42. Claussnitzer, M. et al. FTO obesity variant circuitry and adipocyte browning in humans. N. Engl. J. Med. 373, 895–907 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Regev, A. et al. The Human Cell Atlas. eLife 6, e27041 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  44. Stegle, O., Parts, L., Piipari, M., Winn, J. & Durbin, R. Using probabilistic estimation of expression residuals (PEER) to obtain increased power and interpretability of gene expression analyses. Nat. Protoc. 7, 500–507 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

We gratefully acknowledge J. Pritchard, H. Tang and members of the laboratory of N. Zaitlen for helpful discussions. This work was funded in part by the Natural Sciences and Engineering Research Council of Canada (NSERC) (grant PGSD3-476082-2015 to M.W.); a Stanford Bio-X Bowes fellowship (to M.W.); a Stanford Graduate Fellowship (to N.S.-A.); a National Defense Science & Engineering Grant (to N.S.-A.); NIH grants 1DP2OD022870 and U01HG009431 (to A.K.), 1U24HG008956 and 5U01HG009080 (to M.A.R.), R01HG009120 and R01MH115676 (to B.P.), R01MH107666, R01MH101820 and P30DK20595 (to H.K.I.), and R01HL125863 and R21TR001739 (to J.L.M.B.); NHGRI grant R01HG010140 (to M.A.R.); Leducq Foundation grant 12CVD02 (to J.L.M.B.); and American Heart Association grant A14SFRN20840000 (to J.L.M.B.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

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M.W., M.A.R. and A.K. conceived the study. M.W., N.M. and A.N.B. performed analyses. N.S.-A., D.A.K. and D.G. provided intellectual input. R.E., A.R., T.Q., K.H. and J.L.M.B. provided assistance with analysis of the STARNET dataset. H.K.I., B.P., M.A.R. and A.K. supervised the study. M.W., H.K.I., B.P., M.A.R. and A.K. wrote the manuscript. All authors reviewed the manuscript.

Corresponding authors

Correspondence to Johan L. M. Björkegren, Hae Kyung Im, Bogdan Pasaniuc, Manuel A. Rivas or Anshul Kundaje.

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Wainberg, M., Sinnott-Armstrong, N., Mancuso, N. et al. Opportunities and challenges for transcriptome-wide association studies. Nat Genet 51, 592–599 (2019). https://doi.org/10.1038/s41588-019-0385-z

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