Abstract
Clinical GATA2 haploinsufficiency results in immunodeficiency that evolves to leukemia. How GATA2 haploinsufficiency disrupts the functionality of hematopoietic stem/progenitor cells (HSCs/HSPCs) to facilitate pre-leukemia development is poorly defined. Using a hematopoietic-specific conditional mouse model of Gata2 haploinsufficiency, we identified pervasive defects in HSPC differentiation in young adult Gata2 haploinsufficient mice and perturbed HSC self-renewal following transplantation. These alterations aligned with deregulated global DNA damage responses and inflammatory cell signaling from Gata2 haploinsufficient HSCs. We also discovered genetic interplay between Gata2 and Asxl1, a secondary mutation leading to leukemia in GATA2 deficiency syndromes. HSCs from young adult compound Gata2/Asxl1 haploinsufficient mice were hyperproliferative, functionally compromised after transplantation, and displayed a broad pre-leukemia transcriptomic program. Thus, Gata2 haploinsufficiency triggers HSC genomic instability. Our data further suggest that secondary mutations like ASXL1 exploit this impaired HSC genomic integrity to nurture a pre-leukemic state in GATA2 haploinsufficiency syndromes.