Immune defects in Fanconi anemia.

Fanconi anemia (FA) is a genetic disorder characterized by sensitivity to DNA cross-linking agents, multiple congenital anomalies, progressive bone marrow failure, and an increased prevalence of malignancy. The nature of chromosomal instability in FA is better understood today than in the past, but the molecular pathogenesis of bone marrow failure in this disease has not been clarified. Although there is documented evidence that FA hematopoietic stem cells (HSC) have inherent defects that reduce their survival, the potential influence of auxiliary cells on the ability of the FA bone marrow microenvironment to maintain and support HSC in unknown. Historically, FA has not been represented as a disease that affects the lymphoid compartment. In this article we review the results of studies that suggest that the FA immune system is dysfunctional and may contribute to the pathogenesis of both FA bone marrow failure and neoplastic disease.