Juvenile Myelomonocytic Leukemia Facts

About one to two percent of children with leukemia have Juvenile Myelomonocytic Leukemia (JMML), that's only 25 to 50 new cases a year in the United States. It mainly affects children younger than four years of age, with the average age being two years of age. In this disease, myelocytic and monocytic blood cells grow excessively.

Symptoms

Symptoms for JMML are typical of any child with many illnesses, but if these symptoms don't go away on their own quickly, it's best to see your doctor. Typical JMML symptoms are pale skin; fevers; infection; and bleeding of the skin, mouth, and nose. Children with JMML have a cough and fail to gain weight. Many children will develop a red skin rash and enlarged lymph nodes. Some have small yellowish skin tumors and brown spots (called cafe -au-lait spots), which are characteristic of neurofibromatosis. Other symptoms that your doctor will look for include enlarged liver or spleen, and abnormal blood cell counts like high white blood cells (leukocytosis), low red blood cells (anemia), and low platelet count (thrombocytopenia), in addition to having an increased concentration of myelocytes and monocytes.

Diagnosis

Because the symptoms for JMML are so similar to several other illnesses, your doctor doctor will perform a physical exam as well as a complete blood cell count. Other tests make be required.

Risk Factors

There are two conditions that are seemingly related to JMML. Neurofibromatosis type 1 (NF1) is diagnosed in approximately one in 10 patients with JMML. Children with NF1 are at considerable risk for developing JMML.

Infants with Noonan Syndrome are possibly at risk for developing JMML as well, or a similar disorder. Noonan syndrome is characterized by distinct facial features, growth retardation, and heart anomalies. Children with Noonan syndrome who do develop a JMML-like disorder often get better without aggressive treatment by the time the child turns one year.

References

JMML Foundation http://www.jmmlfoundation.org/

Leukemia Lymphoma Society http://www.leukemia-lymphoma.org