What are the myelodysplastic syndromes?
The myelodysplastic syndromes are a group of diseases where the bone marrow fails to make enough healthy blood cells. It is a type of bone marrow failure or cancer. In MDS, the bone marrow makes a large amount of faulty cells and many die before they reach your bloodstream. These faulty or abnormal blood cells are called ‘dysplastic’. As a result, you do not have the right number of healthy blood cells in your bloodstream.
People with MDS often have low blood counts. If the red blood cells are low, it is called anaemia. A low white blood cell count is called leucopenia, while a low platelet count is called thrombocytopenia.
You may have just one type of blood cell affected.
Or you could have all three blood cells reduced. That is, red cells, platelets and white cells.
When all three blood cells are affected, it is called pancytopenia. As well as causing low blood counts, vvMDS can sometimes develop into a form of leukaemia over time.
Usually this is acute myeloid leukaemia (AML). The risk of this occurring depends on the type of MDS you have, but most patients do not go on to develop leukaemia.
It can help to know what exactly your bone marrow does. All blood cells in a healthy person are made in the bone marrow. Bone marrow is the soft spongy tissue that fills the centre of your long bones. The earliest type of cells in your bone marrow are called stem cells. Stem cells develop and mature into red blood cells, white blood cells and platelets.
- Red blood cells carry oxygen to all the tissues in your body.
- White blood cells are involved in fighting infection.
- Platelets are involved in blood clotting.
Once these blood cells are made, they leave your bone marrow and enter your bloodstream. Normally, the cells are made and replaced by your bone marrow when needed. The entire process is very well controlled.
- MDS is a type of bone marrow failure. The bone marrow cannot make enough healthy red blood cells, white blood cells or platelets.
- Bone marrow is the soft spongy tissue that fills the centre of your long bones.
- Some MDS patients may later develop leukaemia.