CRISPR-engineered human GATA2 deficiency model uncovers mitotic dysfunction and premature aging in HSPCs, impairing hematopoietic fitness.

GATA2 deficiency is a monogenic transcriptopathy disorder characterized by bone marrow failure (BMF), immunodeficiency, and a high risk of developing myelodysplastic neoplasms (MDS) and acute myeloid leukemia (AML). Although informative mouse models have been developed, the mechanisms by which GATA2 haploinsufficiency drives disease initiation in humans remain incompletely understood. To address this, we developed a novel humanized model using CRISPR/Cas9 technology to knock-in GATA2-R398W variant in primary cord blood CD34⁺ cells. Additionally, we introduced specific mutations in SETBP1 and ASXL1 to model distinct premalignant stages of GATA2 deficiency. Through clonal competition and serial transplantation assays, we demonstrated that human CD34+ cells harboring the GATA2 mutation exhibit significantly reduced fitness in vivo when compete with wild-type cells. Notably, this fitness disadvantage persists even when GATA2 mutations are combined with oncogenic SETBP1 and ASXL1 drivers, underscoring the dominant, deleterious effect of GATA2 deficiency on hematopoietic stem cell function. Functional in vitro analyses revealed that GATA2-R398W mutation impairs cell proliferation, disrupts cell cycle progression, and induces mitotic defects, which may contribute to hematopoietic stem/progenitor cell loss and impaired self-renewal. Transcriptomic profiles of GATA2-mutant cells revealed that these functional defects are associated with reduced HSC self-renewal capacity and upregulation of the pre-aging phenotype. Our work highlights the feasibility of generating a human GATA2 deficiency model suitable for studying the biological consequences of various GATA2 variants and the generation of a platform to test potential phenotype-rescuing therapeutics.