Schematic diagram summarizing the evolution of cellular deficiency in GATA2 mutation. BM MLPs are rapidly lost even in healthy carriers (see Figure 2). Peripheral blood CD34 counts are elevated in many patients (see examples in Figures 1 and 2) and tend to decline with advancing disease (not shown). Flt3L is progressively elevated, but declines as patients develop MDS (see Figure 4). A rapid rise in CD34⁺ cells and decline in Flt3L may signify the onset of MDS or AML, although AML may occur sporadically without prior cytopenia.