Tandem repeat variation shapes immune cell type-specific gene expression.

Tandem repeat variation across 1,925 individuals is linked to immune cell type-specific gene expression, with 30.7% of 69,000+ single-cell eQTLs specific to one of 28 cell types.

• Why it matters: TRs are highly polymorphic regulators of gene expression, but their immune-cell, cell-type-specific effects have been hard to quantify due to genotyping and analysis challenges.
• What they did: The study generated whole-genome and single-cell RNA-seq from 5.4 million+ blood-derived cells, meta-analyzed 1.7 million+ TR loci, and used cell-state inference plus matched scATAC-seq QTL mapping.
• The result: Fine-mapping implicated 1,490 TRs as candidate causal drivers in 6.1% of tested genes, and colocalization highlighted 200+ genes linking TRs to immune and haematological trait associations.