Abstract
Hematopoietic failure is the predominant clinical manifestation of Fanconi anemia (FA), a rare, recessively inherited disorder. Mutations in 1 of 15 genes that coordinately function in a complex pathway to maintain DNA integrity also predispose patients to constitutional defects in growth and development. The hematologic manifestations have been considered to reflect the progressive loss of stem cells from the postnatal bone marrow microenvironment. Ethical concerns preclude the study of human hematopoiesis in utero. We report significant late gestational lethality and profound quantitative and qualitative deficiencies in the murine Fancc(-/-) fetal liver hematopoietic stem and progenitor cell pool. Fancc(-/-) fetal liver hematopoietic stem and progenitor cells revealed a significant loss of quiescence and decline in serial repopulating capacity, but no substantial difference in apoptosis or levels of reactive oxygen species. Our studies suggest that compromised hematopoiesis in Fancc(-/-) animals is developmentally programmed and does not arise de novo in bone marrow.