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08:40
Chronic Salmonella Infection Induced Intestinal Fibrosis
Published on: September 22, 2019
Cell-type-resolved genetic variation shapes inflammatory bowel disease risk
Tobi Alegbe1,2,3, Bradley T Harris1, Laura Fachal1
1Wellcome Sanger Institute, Hinxton, UK.
Nature
|June 3, 2026
Summary
This study maps gene expression across millions of single cells to pinpoint genetic links to inflammatory bowel disease (IBD). It identifies specific genes and cell types involved in IBD, offering a new framework for understanding complex genetic diseases.
Area of Science:
- Genomics
- Immunology
- Cell Biology
Background:
- Genetic variants in non-coding regions complicate disease gene identification.
- Understanding cell-type-specific gene regulation is crucial for complex diseases like inflammatory bowel disease (IBD).
Purpose of the Study:
- To map cis-expression quantitative trait loci (eQTLs) across single cells to identify effector genes and cell types in IBD.
- To provide a mechanistic link between genetic risk and specific genes/cell types in IBD.
- To develop a framework for interpreting genome-wide association study (GWAS) loci using single-cell eQTL mapping.
Main Methods:
- Single-cell RNA sequencing of intestinal biopsies and blood from 421 individuals (125 with IBD).
- Mapping of cis-expression quantitative trait loci (eQTLs) at single-cell resolution.
- Colocalization analysis of eQTLs with IBD genome-wide association study (GWAS) loci.
Main Results:
- Cell-type-level eQTLs are more distal, enriched in enhancers, and show higher colocalization with IBD GWAS loci compared to tissue-level eQTLs.
- Identified effector genes (e.g., MAML2, PSEN2, ZMIZ1) in myeloid cells, implicating Notch signaling in IBD.
- Identified Wnt-regulated genes (e.g., MYC) in epithelial stem/progenitor cells, suggesting impaired renewal contributes to barrier dysfunction.
Conclusions:
- Single-cell eQTL mapping provides a powerful approach to link genetic risk to specific genes and cell types in complex diseases.
- This study nominates effector genes at over half of known IBD loci, advancing understanding of IBD pathogenesis.
- The findings offer a generalized framework for interpreting GWAS loci in disease-relevant tissues.
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