Signs and symptoms of JMML can develop over weeks or months. The table below lists the most common signs and symptoms of children diagnosed JMML.

Other possible signs and symptoms are:

• Sweating
• Recurrent infections
• Smooth coffee-colored marks on the skin
• Irritability
• Bruising or bleeding
• Diarrhea (sometimes bloody)
• Shortness of breath or wheezing
• Poor weight gain and failure to thrive

These signs and symptoms can also occur from bacterial or viral infections, so your child’s doctors will rule those out while they wait for genetic mutation test results in the cancer cells.

When my son Gregory was 20 months old he had rotavirus, so I was familiar with how he looked and acted when he was severely dehydrated. When he was 3 years old and became dehydrated, lethargic, and had some behavior changes, I took him straight to the pediatrician. He did nasal swabs, didn’t identify the cause, and sent us to the emergency room for fluids. He didn’t perk up like most kids do after getting fluids, so they did some blood tests and told us he either had a viral infection or leukemia. We were admitted and they did numerous tests for viral infections as well as a bone marrow aspiration. We learned it was some type of leukemia. The oncologist on duty had more than 30 years of experience, but he had only seen one child with JMML. But, that’s what he thought it was. They sent the bone marrow cells to another institution for a second opinion, and the consensus was JMML.

The blood of children with JMML often contains the following:

• Low numbers of mature RBCs and platelets
• Higher than normal number of WBCs (usually around 33,000/μL)
• High number of immature monocytes and other WBCs
• Immature RBCs (called nucleated RBCs)