Study of inherited thrombocytopenia resulting from mutations in ETV6 or RUNX1 using a human pluripotent stem cell model

Stem Cell Reports. 2021 Jun 8;16(6):1458-1467. doi: 10.1016/j.stemcr.2021.04.013. Epub 2021 May 20.


Inherited thrombocytopenia results in low platelet counts and increased bleeding. Subsets of these patients have monoallelic germline mutations in ETV6 or RUNX1 and a heightened risk of developing hematologic malignancies. Utilizing CRISPR-Cas9, we compared the in vitro phenotype of hematopoietic progenitor cells and megakaryocytes derived from induced pluripotent stem cell (iPSC) lines harboring mutations in either ETV6 or RUNX1. Both mutant lines display phenotypes consistent with a platelet-bleeding disorder. Surprisingly, these cellular phenotypes were largely distinct. The ETV6-mutant iPSCs yield more hematopoietic progenitor cells and megakaryocytes, but the megakaryocytes are immature and less responsive to agonist stimulation. On the contrary, RUNX1-mutant iPSCs yield fewer hematopoietic progenitor cells and megakaryocytes, but the megakaryocytes are more responsive to agonist stimulation. However, both mutant iPSC lines display defects in proplatelet formation. Our work highlights that, while patients harboring germline ETV6 or RUNX1 mutations have similar clinical phenotypes, the molecular mechanisms may be distinct.

Keywords: ETV6; Runx1; embryonic stem cells; hematopoiesis; iPSCs; megakaryocyte.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Core Binding Factor Alpha 2 Subunit / genetics*
  • Core Binding Factor Alpha 2 Subunit / metabolism
  • ETS Translocation Variant 6 Protein
  • Genetic Predisposition to Disease
  • Hematopoiesis*
  • Humans
  • Induced Pluripotent Stem Cells / metabolism*
  • Megakaryocytes / metabolism*
  • Models, Biological
  • Mutation
  • Phenotype
  • Proto-Oncogene Proteins c-ets / genetics*
  • Proto-Oncogene Proteins c-ets / metabolism
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism
  • Thrombocytopenia / genetics*
  • Thrombocytopenia / metabolism*


  • Core Binding Factor Alpha 2 Subunit
  • Proto-Oncogene Proteins c-ets
  • RUNX1 protein, human
  • Repressor Proteins