Myelodysplastic syndromes (MDS) are a group of diseases that involve dysfunction of the bone marrow. Bone marrow is the tissue found within the bones; its task is to create mature blood cells from stem cells. In all forms of MDS, this normal cell-creation process is disrupted by the overproduction of clones of a single stem cell. This leads to a decrease in production of normal red blood cells, white blood cells, and platelets.

The World Health Organization has classified MDS into eight categories. Some forms are more serious than others; all of them are serious enough to require a physician’s care. Thirty percent of people with MDS develop acute myeloid leukemia (AML). Leukemia is a cancer of the white blood cells and their parent cells. As more is learned about MDS, experts began to see it as a form of cancer.

Location of Active Bone Marrow in an Adult
nucleus factsheet image
Copyright © Nucleus Medical Media, Inc.

The cause of MDS is unknown, but research shows that certain risk factors are associated with the disease.