GATA2 and Decreased total monocyte count: Heterozygous germline mutations in GATA2 lead to complex and heterogeneous clinical phenotypes including MonoMAC syndrome (monocytopenia and mycobacterial infections)/DCML deficiency (dendritic cell, monocyte, B and natural killer (NK) lymphoid deficiency) (2–7), lymphedema (Emberger syndrome) (8, 9) and familial MDS/AML (10).