GATA2 and hairy cell leukemia: Monocytopenia can result from several conditions such as chemotherapy induced myelosuppression, hairy cell leukemia, aplastic anemia, hemodialysis, HIV infection, corticosteroid administration8 and in the MonoMAC syndrome due to haploinsufficiency of GATA2 (located at 3q21.3) leading to GATA2 deficiency that is characterized by disseminated nontuberculous mycobacterial infections or disseminated fungal disease9.