Chronic Myeloid Leukemia
Source: MedlinePlus Health Topics, U.S. National Library of Medicine
What is leukemia? Leukemia is a term for cancers of the blood cells. Leukemia starts in blood-forming tissues such as the bone marrow. Your bone marrow makes the cells which will develop into white blood cells, red blood cells, and platelets. Each type of cell has a different job: White blood cells help your body fight infection Red blood cells deliver oxygen from your lungs to your tissues and organs Platelets help form clots to stop bleeding When you have leukemia, your bone marrow makes large numbers of abnormal cells. This problem most often happens with white blood cells. These abnormal cells build up in your bone marrow and blood. They crowd out the healthy blood cells and make it hard for your cells and blood to do their work. What is chronic myeloid leukemia (CML)? Chronic myeloid leukemia (CML) is a type of chronic leukemia. "Chronic" means that the leukemia usually gets worse slowly. In CML, the bone marrow makes abnormal granulocytes (a type of white blood cell). These abnormal cells are also called blasts. When the abnormal cells crowd out the healthy cells, it can lead to infection, anemia , and easy bleeding . The abnormal cells can also spread outside the blood to other parts of the body. CML usually occurs in adults during or after middle age. It is rare in children . What causes chronic myeloid leukemia (CML)? Most people with CML have a genetic change called the Philadelphia chromosome. It's called that because researchers in Philadelphia discovered it. People normally have 23 pairs of chromosomes in each cell. These chromosomes contain your DNA (genetic material). In CML, part of the DNA from one chromosome moves to another chromosome. It combines with some DNA there, which creates a new gene called BCR-ABL. This gene causes your bone marrow to make an abnormal protein. This protein allows the leukemia cells to grow out of control. The Philadelphia chromosome isn't passed from parent to child. It happens during your lifetime. The cause is unknown.