Germline mutations in GATA2 predispose patients to familial myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) (3), “MonoMAC” syndrome of monocytopenia with predisposition to non-tuberculous mycobacterial infection (4, 5), Emberger syndrome (1), deafness, lymphedema, and the syndrome of dendritic cells (DCs), monocytes, and B and natural killer (NK) lymphoid deficiency (“DCML deficiency”) (6). The gene discussed is GATA2; the disease is Decreased total monocyte count.