Juvenile myelomonocytic leukemia laboratory tests

Diagnosis
The following criteria are required in order to diagnose JMML:

All 3 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)

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>1 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.

Blood tests: A Combined Blood Count (CBC) will be performed on a child suspected of having JMML and throughout the treatment and recovery of a child diagnosed with JMML.

NOTE: JMML can show many of the same signs as infectious diseases like Epstein-Barr virus, cytomegalovirus, human herpesvirus 6, histoplasma, mycobacteria, and toxoplasma. Therefore, it is important that your doctor rule out these other potential causes of your child’s symptoms during the diagnosis process.