Synthesis of 53 tissue and cell line expression QTL datasets reveals master eQTLs

Area of Science:

• Genetics
• Genomics
• Human Biology

Background:

• Gene expression studies identify expression quantitative trait loci (eQTLs) that offer insights into disease risk mechanisms.
• Limited systematic characterization of eQTLs across diverse human cell and tissue types exists.
• This study synthesized eQTL data from over 50 datasets, including new primary data from brain, kidney, and peripheral plaque samples.

Purpose of the Study:

• To discover features of human eQTLs by synthesizing existing and new data.
• To systematically characterize eQTL results across various human cell and tissue types.
• To understand the role of eQTLs in human trait variability and potential adaptive origins.

Main Methods:

• Synthesis of eQTL results from >50 datasets, including new primary data.
• Analysis of 45 human Genome-Wide Association Studies (GWAS) scans.
• Comparison of eQTL enrichment with genetic mapping studies and regulatory features.

Main Results:

• A substantial number of robust cis-eQTLs and fewer trans-eQTLs were found to be consistent across tissues.
• eQTLs are enriched among positive signals in genetic mapping studies and account for significant human trait effects.
• Tissue-ubiquitous cis-eQTLs are enriched for genes involved in xenobiotic metabolism and mitochondrial function, suggesting adaptive origins; some coincide with human lineage selection regions.

Conclusions:

• Expression QTLs are crucial for interpreting human trait variability and may explain more phenotypic variation than protein-coding variants.
• The synthesis highlights strong cis-eQTLs with potential biological roles, serving as positive controls for future studies.
• Tissue-ubiquitous eQTLs may have adaptive origins in humans, and expanded eQTL coverage will further illuminate human gene regulation.