Juvenile myelomonocytic leukemia (JMML) is a rare disease accounting for less than 1% of all leukemias affecting children. This is cancer of the blood when the immature white blood cells (monocytes) are produced in excess and continue to crowd out the normal cells in the bone marrow. This is considered to be the serious form of chronic leukemia. Childhood leukemia is estimated to affect around 3,000 children annually in the United States.
Causes
Although the exact cause of JMML is not known, it is estimated that around 75% of the children diagnosed with JMML present genetic abnormalities. Generally, individuals with cancer, including JMML are associated with the abnormal changes with certain cells called the oncogenes or tumor suppressor genes. The oncogenes are responsible for the control of cell growth and the tumor suppressor gene controls the cell division. The exact changes of these genes are however, not known.
Symptoms
The symptoms develop as the result of the problem with the function of the bone marrow and the lack or the abnormal function of the red cells. Some of the symptoms of JMML include paleness of the skin from anemia, weakness, shortness of breath with minimal exercise and fatigue. The abnormal function of the white cell and their low quantity can cause fever, mouth ulcers and recurring infections particularly chest infections. The abnormal function of the platelet or its low quantity can cause easy bruising, bleeding from the gums and development of small red dots on the skin. The affected case can also present enlarged liver, spleen and lymph nodes. Additional related problems include low appetite, poor weight gain and developmental delay.
Diagnosis
The diagnosis is based on the evaluation of the individual’s history, identification of the symptoms associated with JMML and with various specialized tests. In some cases, JMML may be identified with the routine blood tests that are done for other conditions. The complete blood count (CBC) measures that size, maturity and the quantity of the different blood cells. Additional blood tests may be necessary to determine the liver and the kidney functions. The bone marrow aspiration and biopsy may be required that removes a sample of the fluid and the marrow cells for analysis. The spinal tap / lumbar puncture may be done to measure the pressure of the spinal canal and the sample of cerebral spinal fluid will be tested for infections or other problems. Additional tests may be required based on the child’s individual situation.
Treatment
The treatment is based on the age of the child, their medical history, the extent of the disease and their tolerance to various procedures. The treatment options for JMML are often limited. The chemotherapeutic regimens had limited success with treating JMML but may be used initially to keep the condition under control. The only potential cure for JMML is hematopoietic stem cell transplantation which is a type of bone marrow transplant.
References
https://rarediseases.org/rare-diseases/juvenile-myelomonocytic-leukemia/
http://www.childrenscancer.org/main/juvenile_myelomonocytic_leukemia_jmml/
