What is the Meaning of Myelodysplastic Syndrome?

Key Facts About Myelodysplastic Syndrome

Also called myelodysplastic neoplasms, myelodysplastic syndromes (MDS) refer to a collection of rare yet life-threatening blood diseases in which the bone marrow produces disrupted, oversized, or malfunctioning cells. Consequently, the body contains fewer red blood cells, white blood cells, or platelets, which can lead to illnesses like anaemia, infections, and bleeding disorders.

Some of the abnormal cells can lose their function or die prematurely, and in most patients, MDS can turn into a more dangerous cancer called acute myeloid leukaemia (AML). MDS is a rare occurrence, with estimates ranging between 0.06 and 0.26 per 100,000 individuals globally.

Read on to learn more about this disorder alongside its types, symptoms, and causes. 

How Many Types of Myelodysplastic Syndrome are There?

MDS is divided into six main types, according to the World Health Organisation (WHO). These include:

1. Refractory Cytopenia with Unilineage Dysplasia (RCUD) : This type of MDS involves an individual line of blood cells (red cells, white cells, or platelets). For instance, if red blood cells are the only ones affected, it manifests as refractory anaemia with evident anomalies in their structure and function.
2. Refractory Anaemia with Ring Sideroblasts (RARS) : RARS patients are afflicted mainly with anaemia due to defective production of red blood cells (RBCs). One of the most significant characteristics is ring sideroblasts—red blood cell precursors that have iron-carrying mitochondria in a ring configuration outside the nucleus.
3. Refractory Cytopenia with Multilineage Dysplasia (RCMD) : This type entails abnormal growth in more than one type of blood cell, most often targeting red cells, white cells, and platelets. It is more serious and has a greater likelihood of developing into acute leukaemia.
4. Refractory Anaemia with Excess Blasts (RAEB) : Characterised by increased numbers of immature blood cells (blasts) in the bone marrow. It is sub-classified as Refractory Anaemia with Excess Blasts-1 (RAEB-1) and Refractory Anaemia with Excess Blasts-2 (RAEB-2). They both are characterised by 5-9% blasts and 10–19% blasts in the bone marrow, respectively.
5. MDS with Isolated del(5q) : A type of MDS is characterised by a typical genetic abnormality—elimination of the long arm of chromosome 5. The patients usually exhibit signs of anaemia and require RBC transfusions. In general, MDS with isolated del(5q) usually has a good prognosis compared to other types.
6. Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN): This hybrid group of diseases has characteristics from both MDS and a second group known as myeloproliferative neoplasms. Some include chronic myelomonocytic leukaemia (CMML), atypical chronic myeloid leukaemia (aCML), and juvenile myelomonocytic leukaemia (JMML). These conditions are more complex and require precise diagnosis and treatment.

What are the Symptoms of Myelodysplastic Syndrome (MDS)?

Listed below are the most common symptoms of MDS:

• Persistent fatigue and lack of energy
• Generalised weakness and reduced stamina
• Dizziness or lightheadedness
• Pale or sallow skin due to a low red blood cell count
• Shortness of breath, especially with minimal activity
• Chest pain or heart palpitations
• Lightheadedness and poor concentration
• Frequent infections that may be severe or hard to treat
• Fever or flu-like symptoms
• Delayed wound healing due to immune compromise
• Easy or excessive bruising
• Prolonged bleeding from minor cuts
• Bleeding gums or frequent nosebleeds
• Small red or purple spots under the skin (petechiae)
• Gastrointestinal bleeding in more advanced cases
• Enlarged liver or spleen (in rare or advanced cases)
• Bone or joint pain (in some subtypes)

What are the Causes and Risk Factors of Myelodysplastic Syndrome?

While the exact cause of MDS is often unknown, research has revealed certain factors that may increase the risk of developing this bone marrow disorder:

• Past Cancer Treatment: Those who have already received chemotherapy or radiation treatment, particularly in combination with each other, are at much higher risk for developing secondary or therapy-associated MDS.
• Chemical Exposure: Chronic exposure to industrial chemicals such as benzene, pesticides, solvents, and heavy metals has been closely associated with damage to DNA in bone marrow cells.
• Bone Marrow Abnormalities: Underlying conditions like aplastic anaemiaor paroxysmal nocturnal haemoglobinuria (PNH) may interfere with normal blood production and predispose to MDS.
• Abnormal Functioning of the Immune System: Autoimmune disorders and immunologically related diseases can impair normal bone marrow cells, possibly inducing MDS in some patients.
• Smoking: Smoking cigarettes is directly associated with an increased risk of MDS because harmful chemicals affect bone marrow function.
• Genetic Mutations and Disorders: Though MDS is not inherited, certain acquired mutations (e.g., TP53, TET2) and a few inherited syndromes may increase the likelihood of the disease.
• Age and Gender: MDS is more prevalent in men than women. Additionally, it is primarily found in older individuals, with most of the diagnoses occurring in people over 60 years old.
• Infections: Viral infections like HIV and certain herpesviruses are a few potential risk factors that can lead to this condition.
• Damage to Stem Cell DNA: In the majority of instances, MDS results from damage to the DNA of bone marrow stem cells and their inability to produce healthy blood cells.

Myelodysplastic syndrome (MDS) is a complex blood disorder that requires prompt diagnosis and individualised treatment. With effective management, most individuals can lead a good quality of life. However, such diseases usually require expensive treatments and long-term management.

Thus, having a comprehensive health insurance plan that provides coverage for MDS and related disorders is crucial. It will enable you to access timely medical treatment, along with coverage for doctor consultations, diagnostic tests, and more.  

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