GATA2 and Decreased total monocyte count: Inherited or sporadic heterozygous mutations in the transcription factor GATA2 (guanine-adenine-thymine-adenine 2) causes a germline disease manifesting a wide spectrum of clinical phenotypes including monocytopenia and Mycobacterium avium complex (MAC) infection (MonoMAC) syndrome [1, 2]; dendritic cell (DC), monocyte, B and natural killer (NK) lymphoid (DCML) deficiency [3]; familial myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) [4]; Emberger syndrome (congenital deafness, primary lymphedema, and predisposition to MDS and AML) [5]; and classic NK cell deficiency [6].