This includes:
15-20% of patients with neurofibromatosis 1 (NF1)
25% of patients with mutations in one of the RAS family of oncogenes (only in their leukemia cells)
Another 35% of patients with a mutation in a gene called PTPN11 (again, only in their leukemia cells). Diagnosis
The following criteria are required in order to diagnose JMML:All 4 of the following:

No Philadelphia chromosome or BCR/ABL fusion gene. Peripheral blood monocytosis >1 x 109/L. Less than 20% blasts (including promonocytes) in the blood and bone marrow (blast count is less than 2% on average)
SplenomegalyAt least one of:
Mutation in RAS or PTPN11
Diagnosis of neurofibromatosis 1
Chromosome 7 monosomyOr two or more of the following criteria:

Hemoglobin F increased for age. Immature granulocytes and nucleated red cells in the peripheral blood. White blood cell count >10 x 109/L. Clonal chromosomal abnormality (e.g., monosomy 7). Granulocyte-macrophage colony-stimulating factor (GM-CSF) hypersensitivity of myeloid progenitors in vitro.These criteria are identified through blood tests and bone marrow tests. The differential diagnosis list includes infectious diseases like Epstein–Barr virus, cytomegalovirus, human herpesvirus 6, histoplasma, mycobacteria, and toxoplasma, which can produce similar symptoms.
Relapse rate has been recorded as high as 50%. Many children have been brought into remission after a second stem cell transplant.After bone marrow transplant, the relapse rate for children with JMML may be as high as 50%. Relapse often occurs within a few months after transplant and the risk of relapse drops considerably at the one-year point after transplant. A significant number of JMML patients do achieve complete remission and long-term cure after a second bone marrow transplant, so this additional therapy should always be considered for children who relapse. Frequency
JMML accounts for 1–2% of childhood leukemias each year; in the United States, an estimated 25-50 new cases are diagnosed each year, which also equates to about 3 cases per million children. There is no known environmental cause for JMML. Since about 10% of patients are diagnosed before 3 months of age, it is thought that JMML is a congenital condition in these infants

History
Juvenile myelomonocytic leukemia (JMML) is a myelodysplastic and myeloproliferative disorder. The diagnostic criteria were originally laid down by Neimeyer et al. in 1997 and 1998 and were incorporated in the WHO classification in 2008. See also
List of cutaneous conditions
Hematologic disease
List of cancer types

References


== External links ==