PTPN11 and myelodysplastic syndrome: In addition, PTPN11 mutations have been identified in pediatric acute leukemias, such as myelodysplastic syndrome (MDS) (10%) [18, 19], B cell acute lymphoblastic leukemia (B-ALL) (7%) [20, 63], and acute myeloid leukemia (AML) (4%) [64].