Causes of Myelodysplasia

Myelodysplasia is a group of conditions marked by the ineffective production of blood cells, including white blood cells (important for the immune system), red blood cells (critical for oxygen transport), and platelets (important for clotting). Patients with myelodysplasia suffer from anemia and require frequent blood transfusions. Myelodysplasia also can develop into acute myelogenous leukemia.

Inherited Genetic Defect

• Some cases of myelodysplasia are caused by a deletion on the fifth chromosome. This mutation can be passed on throughout a family and results in low numbers of red blood cells.

Acquired Genetic Mutations

• Genetic mutations can also accumulate over time which prevents the bone marrow from making new red blood cells, leading to myelodysplasia.

Chemotherapy

• Certain drugs used for cancer chemotherapy, especially those that can damage the bone marrow can cause myelodysplasia. Some classic examples of these chemotherapeutic agents are procarbazine, mechlorethamine and chlorambucil.

Stem Cell Treatment

• In some cases, patients who have received stem cell transplants can also be affected with myelodysplasia as a result of the medications administered before the transplant. Because these medications suppress the immune system to allow the transplant to be successful, they can cause bone marrow damage and, as a result, myelodysplasia.

Toxins

• Exposure to high doses of radiation, benzene and other toxic chemicals can damage the bone marrow and lead to myelodysplasia. There is also evidence that exposure to pesticides and heavy metals can damage the bone marrow.