According to St. Jude’s Children’s Research Hospital, myelodysplasia describes disorders where bone marrow fails to produce sufficient quantities of normal blood cells. Known as MDS, these myelodysplastic syndromes are more common in men and are typically found in adults over the age of 50. Mayo Clinic notes additional risk factors include prior chemotherapy or radiation therapy, exposure to heavy metals or exposure to certain chemicals.
Mayo Clinic lists fatigue, uncharacteristic paleness due to anemia, petechiae and frequent infection as symptoms of MDS. When these symptoms are present in conjunction with risk factors, a visit to a physician is advisable. Secondary MDS is caused by chemotherapy or radiation and is considered unique to primary MDS, which has no known cause.
There are seven types of MDS according to the American Cancer Society, which uses the World Health Organization MDS classification system. The National Cancer Institute indicates that in unclassifiable MDS, blasts in the bone marrow and blood are normal, but the disease does not fit any of the other types. It further states that refractory anemia with ring sideroblasts involves insufficient red blood cells, which causes the patient to have anemia and too much iron in the red blood cells.
According to Mayo Clinic, there is no known cure for MDS as of 2014, so treatment focuses on complications of the disorder. Those treatments include medication, blood transfusion and bone marrow transplants.