NEW 12/11/2014…If your child is suspected of having JMML or was recently diagnosed, please consider participating in a research study aimed at better understanding of the genetic and biochemical changes that can lead to JMML. With your help, researchers around the world hope to study the cells affected by JMML to eventually lead to a cure.

The following criteria are required in order to diagnose JMML, based on consensus diagnostic criteria from the 2009 JMML Symposium (from de Vries 2010 Haematologica Vol 95: pp 179-82). 

Category 1 criteria are mandatory; if category 2 criteria (oncogenetics) are negative, 2 of category 3 criteria need to be fulfilled.

 Category 1  Category 2  Category 3
 ALL of the following  At least 1 of the following **  At least 2 of the following
(Enlarged spleen)
 Somatic mutation in RAS or PTPN11  Circulating myeloid precursors
 ANC >1000/µL
(absolute neutrophil count)
 Clinical diagnosis of NF1 or mutated NF1 gene  WBC >10,000/µL
(white blood count)
 Blasts in PB/BM < 20%  Germline mutation in CBL  Increased Hgb F for age
 Absence of the t(9;22) or BCR/ABL fusion gene  Monosomy 7  Clonal cytogenetic abnormality
     GM-CSF hypersensitivity***

*Some children initially present without splenomegaly, but splenomegaly develops within few weeks of diagnosis.
** NEW 12/11/2014…One way a child's doctor can request these tests from the University of California San Francisco (UCSF) by using this Clinical Lab Test Requisition.  These tests may also be performed by other companies.
***This test is not available in many locations.

These criteria are identified through blood tests and bone marrow tests.

Blood tests: A Complete 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. The blood components checked in a CBC and some of the more common reference values in infants and children are listed in the table below*:

Blood Count Age 3-6 months

Age 6 months - 2 years  Age 2-5 years
 HGB (Hemoglobin) 9.5-13.5 (g/DL)
 10.5-13.5  11.5-15.5
 HCT (Hematocrit)  29-41 (%)

 33-49  34-40
 RBC (Red Blood Cells) 3.1-4.5 (x106/µL)  3.7-5.3  3.9-5.3 
 MCV  74-108 (fl)  70-86  75-87
 MCH  25-35 (pg)  23-31  24-30
 MCHC  30-36 (%)  30-36  32-36
 RDW  11.5-16.0 (%)  11.5-16.0  11.5-15.0
 WBC (White Blood Cells)  6.0-17.5 (x103/µL)  6.0-17.0  5.5-15.5
 Segmented Neutrophils
 13-33 (%)

 Band Neutrophils  0-11 (%)  0-11  0-11
 Eosinophils  0-3 (%)  0-3  0-3
 Basophils  0-1  0-1  0-1
 Lymphocytes   41-71 (%)   45-76  35-65
 Monocytes  4-7 (%)  3-6  3-6
 Platelets  250-450 (x103/µL)  250-450    250-450

*These reference values and more are at the Children's Hospitals and Clinics of Minnesota website.

Suggestions for preparing a child for a CBC, biopsy, xray or other procedure:

For more information on Bone Marrow aspirations and biopsies, see:

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.

If you need help with some of the medical terms included in these pages, please use the NIH MedlinePlus Medical Dictionary

The medical information on this page was last reviewed in January 2013 by Dr. Christian Flotho, Division of Pediatric Hematology and Oncology, University of Freiburg, Freiburg, Germany. NEW information on the UCSF Clinical Lab Test Requisition and genetic research studies was updated in December 14 by Fred Dini, The JMML Foundation.

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