Types of Myelodysplastic Syndromes
The World Health Organization divides myelodysplastic syndromes into subtypes based on the type of blood cells i.e red blood cells, white blood cells and platelets involved. These different types of Myelodysplastic syndrome include:
- Myelodysplastic syndromes with single-lineage dysplasia: One blood cell type — white blood cells, red blood cells or platelets — is low in number and appears abnormal under the microscope.
- Myelodysplastic syndromes with multilineage dysplasia: In this subtype, two or three blood cell types are abnormal.
- Myelodysplastic syndromes with ring sideroblasts: This subtype involves a low number of one or more blood cell types. A characteristic feature is that existing red blood cells in the bone marrow contain rings of excess iron.
- Myelodysplastic syndromes with isolated del (5q) chromosome abnormality: People with this subtype have low numbers of red blood cells, and the cells have a specific mutation in their DNA.
- Myelodysplastic syndromes with excess blasts: In this subtype, any of the three types of blood cells — red blood cells, white blood cells or platelets — might be low and appear abnormal under a microscope. Very immature blood cells (blasts) are found in the blood and bone marrow.
- Myelodysplastic syndromes, unclassifiable: In this subtype, there are reduced numbers of one or more types of mature blood cells and the cells might look abnormal under the microscope. Sometimes the blood cells appear normal, but analysis might find that the cells have DNA changes that are associated with myelodysplastic syndromes.