Table 2.

Diagnosis criteria for juvenile myelomonocytic leukemia (JMML) per the 2016 revision to the World Health Organization classification [10].

Category 1 (all are required)	Clinical and hematologic features	Absence of the BCR-ABL1 fusion gene >1 × 10/L circulating monocytes <20% blasts in the peripheral blood and bone marrow Splenomegaly
Category 2 (one is sufficient)	Genetic studies	Somatic mutation in KRAS, NRAS, or PTPN11 (germline mutations need to be excluded) Clinical diagnosis of NF-1 or NF-1 gene mutation Germline CBL mutation and loss of heterozygosity of CBL
Category 3 (patients without genetic features must have the following in addition to category 1)	Other features	Monosomy 7 or other chromosomal abnormality or at least 2 of the criteria given as follows: circulating myeloid or erythroid precursors, increased hemoglobin F for age, hyperphosphorylation of STAT-5, GM-CSF hypersensitivity

NF-1, neurofibromin-1; CBL, casitas B-lineage lymphoma; PTPN11, protein tyrosine phosphatase nonreceptor type; KRAS, Kirsten rat sarcoma; NRAS, neuroblastoma rat sarcoma.