BCR and juvenile myelomonocytic leukemia: According to the International JMML Working Group criteria, it is not difficult to confirm a diagnosis of JMML.[6,10,11] The clinical manifestation of JMML can be somewhat nonspecific, but a diagnosis must include all of the following criteria: splenomegaly, an absolute monocyte count >1000/μL, higher fetal hemoglobin levels than normal for the age of the patient, <20% myeloblasts in the blood and bone marrow, and the absence of a t (9;22) or BCR/ABL fusion gene.