Yao, D. W. et al. Nat. Genet. 52, 626–633 (2020).
Genome-wide association studies (GWAS) and expression quantitative trait locus (eQTL) analyses can identify genetic variants associated with complex traits and gene expression, respectively. Previous studies showed overlap between these two types of signal, suggesting a potential impact of gene expression levels on phenotypic variability. Although several strategies exist for quantifying this effect, distinguishing directionally mediated effects from alternatives such as pleiotropy and linkage is difficult. Yao et al. define heritability mediated by the cis genetic component of gene expression levels and develop a statistical method called mediated expression score regression (MESC) for estimation using GWAS and cis-eQTL summary statistics. MESC does not depend on significance thresholds to filter genes or SNPs and achieves unbiased estimates with well-calibrated standard errors. The researchers analyzed data from 42 traits and 48 tissues, and found only about 11% of heritability was mediated by assayed gene expression levels.
About this article
Cite this article
Tang, L. Disease heritability explained by eQTLs. Nat Methods 17, 655 (2020). https://doi.org/10.1038/s41592-020-0897-6