Myelodysplastic syndrome (MDS) is one of many diseases we treat with blood and marrow transplant at University of Minnesota Medical Center.

Myelodysplastic diseases are a group of diseases in which the bone marrow makes too many white blood cells. Normally, the bone marrow makes blood stem cells (immature cells) that become mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. The lymphoid stem cell develops into a white blood cell. The myeloid stem cell develops into one of three types of mature blood cells:

• Red blood cells that carry oxygen and other materials to all tissues of the body
• White blood cells that fight infection and disease
• Platelets that help prevent bleeding by causing blood clots to form

In myelodysplastic diseases, the blood stem cells do not mature into healthy red blood cells, white blood cells, or platelets. The immature blood cells, called blasts, do not work the way they should and die in the bone marrow or soon after they enter the blood. As a result, there are fewer healthy red blood cells, white blood cells, and platelets.

Myelodysplastic diseases may progress to acute leukemia. For more information on MDS, visit the University of Minnesota Masonic Cancer Center site.