Chronic myelogenous leukemia (CML) is a cancer of the blood and bone marrow. The bone marrow makes abnormal blood cells including:

  • Myeloblasts—a type of white blood cell, fights infection
  • Red blood cells (RBCs)—carry oxygen
  • Platelets—makes blood clot, stops bleeding in cuts or bruises

CML progresses gradually. It is often slow growing for many years. Over time, it may change into acute myelogenous leukemia (AML). This is a more aggressive type of leukemia. It progresses more rapidly and is more serious.

Cancer occurs when cells in the body become abnormal. They divide without control or order. Leukemia is cancer of the white blood cells and their parent cells. Leukemia cells do not function normally. They cannot do what normal blood cells do. In this case, they can not fight infections. This means that the person is more likely to become infected with viruses or bacteria. The cancerous cells also overgrow the bone marrow. This forces other normal cells, like platelets out. Platelets are needed to help the blood clot. As a result, people with leukemia may bleed more easily.

White Blood Cells
White Blood Cells
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CML is almost always associated with a gene mutation. The gene is in a chromosome called the Philadelphia chromosome. This mutation occurs during life. It is not passed from parent to child. In most cases, the cause of the mutation is not known. Studies show that exposure to large doses of radiation is associated with development of CML. It may be found in survivors of nuclear accidents or of atomic bomb blasts. However, most patients with the condition have not been exposed to radiation.