Myelodysplastic syndromes are a group of blood disorders caused by improperly formed blood cells, or blood cells that do not function correctly, which are then released into the blood. This production of faulty cells occurs as a result of a problem or problems with the bone marrow. 

There are several forms of myelodysplastic syndrome, which are normally divided according to the type of blood cell affected (red cells, white cells, or platelets). The cause of myelodysplastic syndromes varies, but risks factors include being over 60 years of age, exposure to certain chemicals or heavy metals, and treatment with chemotherapy or radiation therapy. 

Symptoms of myelodysplastic syndrome often include fatigue, shortness of breath, anemia, unusual bruising or bleeding, unusual paleness, and frequent infections. The susceptibility to infection often occurs when the myelodysplastic syndrome affects the white blood cell count.  

There is no cure for myelodysplastic syndromes, but treatment can alleviate the symptoms and reduce the risk of complications as a result of the disease. Treatment options include blood transfusions, bone marrow transplants, and medication to increase blood cell levels or suppress the immune system. Drug classes used to treat myelodysplastic syndromes are protein kinase inhibitors, immunomodulators, angiogenesis inhibitors, and pyrimidine analogs.