What are the types of MDS?


On this page:

What are the types of MDS?

There are different types of MDS depending on how it affects your blood cells and bone marrow. In some types of MDS you will have a high number of blast cells which are white blood cells which haven’t developed properly. In others, your blood cells or chromosomes may be abnormal in some way. 

The different types of MDS are classified into 6 subtypes under a World Health Organization (WHO) classification system: 

  1. MDS with single lineage dysplasia (MDS-SLD) 
  2. MDS with multilineage dysplasia (MDS-MLD)
  3. MDS with ring sideroblasts (MDS-RS)
  4. MDS with isolated del (5q)
  5. MDS with excess blasts (MDS-EB)
  6. MDS unclassifiable (MDS-U)

Understanding MDS subtypes

  • Dysplasia means the size, shape or look of blood cells are abnormal.
  • Ring sideroblasts are red blood cells with ring-shaped iron deposits in them.
  • MDS with deletion 5q means part of chromosome 5 is missing.

Your doctor will explain which type of MDS you have. If you are confused or have more questions, ask your doctor or specialist nurse. You can also speak to a nurse by calling our Support Line on 1800 200 700 or by visiting a Daffodil Centre.

Low-risk or high-risk MDS

Low- or high-risk MDS refers to your chance of developing a blood cancer called acute myeloid leukaemia (AML). The risk of this happening depends on the type of MDS you have, but most patients do not go on to develop AML.

  • Low risk: You have a 1 in 10 chance of developing AML. This includes the following types: MDS-SLD, MDS-MLD, MDS-RS and the 5q-syndrome.
  • High risk: The risk of developing leukaemia is much higher in this group. This includes MDS-EB.

The treatment of low-risk and high risk-disease is often different. Your doctor may use the WHO classification to decide if your MDS is low risk or high risk, and also the Revised International Prognostic Scoring System (IPSS).

Revised International Prognostic Scoring System (IPSS-R)

As well as the different types of MDS, doctors may use the IPSS-R to look at how the disease is most likely to develop, based on:

  • The number of cell types that are low in your blood (cytopenia)
  • The amount of blasts (immature cells) in your blood and bone marrow
  • Any chromosome changes (cytogenetics)

Each factor gets a score. Together, the scores tell which risk groups you fall into. 

Should I ask about my prognosis?

If your prognosis is better than expected, you may feel more hopeful about your illness and your future. You may feel more in control by having as much information as possible. Or you may not want to know about your prognosis. You may prefer not to think about the future too much or you may worry how you will cope if you get bad news.

For more information

Icon: Phone


1800 200 700

Icon: Email