Myelodysplastic Syndromes (MDS)

Myelodysplastic syndromes (MDS) are diseases of the blood and bone marrow. In a healthy person, bone marrow stem cells divide to create daughter cells that produce all of the mature cells found in our blood: red blood cells (which carry oxygen), white blood cells (which fight infection), or platelets (which form blood clots to stop bleeding).

In people with MDS, the blood stem cells have become abnormal and have difficulty producing mature blood cells. These abnormal cells either die in the bone marrow or soon after they enter the blood/ This leads to a lack of healthy cells and potential health complications, including infection, anemia or bleeding.

There are several types of MDS defined by features of cells in the blood and bone marrow. They include:

• Refractory anemia
• Refractory anemia with ringed sideroblasts
• Refractory anemia with excess blasts
• Refractory anemia with excess blasts in transformation
• Refractory cytopenia with multilineage dysplasia
• Myelodysplastic syndrome that is associated with an isolated del(5q) chromosome abnormality
• Unclassifiable myelodysplastic syndrome
• MDS and myeloproliferative overlap syndromes

The symptoms of MDS are often vague and can be caused by unrelated disorders. These symptoms may include:

• Shortness of breath
• Weakness or fatigue
• Pale skin
• Easy bruising or bleeding
• Flat, pinpoint spots under the skin caused by bleeding
• Fever or frequent infections

MDS usually occurs in people in their 60s or older. Exposure to chemotherapy, radiation therapy or certain chemicals can predispose people to MDS. But in most patients, there is no identifiable factor responsible for their disease.