Chronic myeloid leukemia (CML) is a type of leukemia that starts in myeloid cells in the bone marrow. It’s also known as chronic myelogenous leukemia. It starts in cells that normally help the body fight infections.
There is a change in a chromosome in the cells of almost all patients with CML. The change is called the Philadelphia chromosome. It creates an abnormal gene called BCR-ABL. This causes the leukemia cells to grow out of control.
As the leukemia cells grow, they can crowd out the normal cells in the bone marrow. This can lead to not enough different types of blood cells. People with CML have too many white blood cells in their blood.
CML is a type of chronic leukemia. This means it tends to grow slowly. CML does not always cause symptoms right away. Some people with CML have no symptoms when CML is diagnosed.