Integrative GWAS and snRNA-seq Reveal a Mesenchymal-Like Endothelial Signature in Moyamoya Disease

Yudai Hirano1,2, Satoru Miyawaki1, Kyuto Sonehara2,3,4,5

  • 1Faculty of Medicine, Department of Neurosurgery (Y.H., S.M., H. Imai, H.H., H.O., S.O., S.T., Y. Sakai, D.S., T.T., S.H., S. Koizumi, S.D., Y. Shinya, S. Kiyofuji, H.N., N.S.), The University of Tokyo, Japan.

Stroke
|March 2, 2026
PubMed
Abstract

Insights

Moyamoya disease (MMD) genetic risk is linked to a protective RNF213 variant, distinct from the major risk allele. This genetic risk converges on an expanded mesenchymal-like endothelial cell (MEC) state in MMD patients.

Area of Science:

  • Genetics
  • Vascular Biology
  • Genomics

Background:

  • Moyamoya disease (MMD) has a significant genetic component, primarily linked to the RNF213 variant rs112735431.
  • The complete genetic architecture and involved vascular cell types in MMD are not fully understood.

Purpose of the Study:

  • To investigate the broader genetic landscape of Moyamoya disease.
  • To identify novel genetic risk factors and understand the cellular mechanisms underlying MMD pathogenesis.

Main Methods:

  • Genome-wide association study (GWAS) in a large Japanese cohort (47,656 individuals).
  • Single-nucleus RNA sequencing (snRNA-seq) of superficial temporal arteries from MMD patients.
  • Cell type-specific enrichment analysis using the Single-Cell Disease Relevance Score.
  • Immunohistochemistry for validation of candidate markers.

Main Results:

  • Identified a novel genome-wide significant signal in the HDAC9-TWIST1 region associated with MMD risk.
  • Discovered a protective RNF213 missense variant (p.Asn1331Gly, rs8074015) mutually exclusive with the major risk allele on haplotypes.
  • snRNA-seq revealed an expanded population of mesenchymal-like endothelial cells (MECs) in MMD patients, characterized by selective FN1 expression and mesenchymal pathway activation.
  • GWAS-prioritized genes were significantly enriched in MECs.

Conclusions:

  • A protective RNF213 variant was identified, which is inversely associated with the major risk allele rs112735431.
  • Genetic risk in Moyamoya disease converges on an expanded mesenchymal-like endothelial cell (MEC) state, highlighting its critical role in pathogenesis.