Myelodysplastic syndrome, or MDS, is a group of diseases in which the bone marrow doesn’t produce enough healthy blood cells. Red blood cells, white blood cells and platelets originate in the marrow and move into the bloodstream when they mature. In MDS, the marrow produces too many immature cells (blasts). These blasts die in the marrow or soon after entering the bloodstream, resulting in too few healthy blood cells and low patient blood counts.
In its mildest form, myelodysplastic syndrome may be only anemia, low platelets or low white blood count, but higher-risk types can progress to acute myeloid leukemia (AML). There is currently no standard system for tracking myelodysplastic syndrome cases, but the American Cancer Society estimates that 10,000 to 15,000 people are diagnosed every year. Ninety percent of myelodysplastic syndrome patients are over the age of 60, and 10-20% of diagnosed cases will progress to AML.