The haematology team has now taken over his care.
Bone marrow aspirate has demonstrated a hypercellular marrow with left shift, and there are increased myeloid and monocyte lineages. Blast count is about 4%. There is occasional evidence of haemophagocytosis and mild erythroid dysplastic features.
Flow cytometry highlights a 5% myeloid blasts in addition to prominent CD14+/CD64+ monocytic population.
Sequencing identified the following variant:
- PTPN11 (NM_002834.3) c.226G>A p.(Glu76Lys)
- Interpretation is that disease associated variants in PTPN11 are seen in approximately 35% of JMML cases. The p.(Glu76Lys) is the most most frequently observed PTPN11 finding in JMML.
- Karyotype: 45, XY, -7 
- FISH: Monosomy 7 [78/100] / BCR-ABL fusion Negative 
Therefore a diagnosis of JMML has been confirmed.
His HbF is 8.5%.
He has been seen by the clinical geneticist and feels there are no concerns. He has also been seen by the cardiologist and had an ECHO which is normal. There is no evidence of neurofibromatosis.
He remains relatively well, although is needing the occasional platelet transfusion and has had one or two chest infections.
1. How do you proceed with treatment? Does the management change if the mutation identified was CBL, or if he has Noonan’s syndrome?
2. What is your opinion on conventional chemotherapy in JMML?
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