Integrative Multi-omic Analysis of Human Platelet eQTLs Reveals Alternative Start Site in Mitofusin 2

Lukas M Simon1, Edward S Chen2, Leonard C Edelstein3

  • 1Department of Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.

Insights

This study reveals a platelet-specific gene regulation mechanism for cardiovascular disease (CVD) risk variant rs1474868, linking it to mitofusin 2 (MFN2) expression and platelet count. These findings enhance understanding of genetic contributions to CVD.

Area of Science:

  • Genomics
  • Cardiovascular Research
  • Platelet Biology

Background:

  • Cardiovascular disease (CVD) is a leading global cause of mortality.
  • Genome-wide association studies (GWASs) have identified numerous genetic loci associated with CVD risk.
  • The functional impact of these genetic variants on disease mechanisms remains largely unclear.

Purpose of the Study:

  • To investigate cis expression quantitative trait loci (eQTLs) in human platelets.
  • To integrate eQTL data with GWAS findings to interpret genetic risk variants for CVD.
  • To identify platelet-specific regulatory mechanisms contributing to cardiovascular health.

Main Methods:

  • Analysis of cis expression quantitative trait loci (eQTLs) in platelets from 154 subjects.
  • In silico validation using allele-specific expression (ASE) analysis.
  • Comparison of platelet eQTLs with Genotype-Tissue Expression (GTEx) data and integration with GWAS results.

Main Results:

  • A significant correlation was observed between the allelic directionality of eQTLs and ASE patterns.
  • Numerous platelet-specific eQTLs were identified, with peaks localizing to gene bodies more frequently than in other tissues.
  • The GWAS-associated variant rs1474868 was linked to an eQTL peak for mitofusin 2 (MFN2), associated with an unannotated platelet-specific MFN2 start site.
  • MFN2 expression levels were significantly associated with platelet count.

Conclusions:

  • The study identifies a novel, platelet-specific regulatory role for MFN2 influenced by the CVD risk variant rs1474868.
  • This research highlights the importance of integrating multi-omic data, including eQTL analysis in relevant tissues, for interpreting GWAS findings.
  • The findings provide a mechanistic link between genetic variation, platelet function, and cardiovascular disease risk.