Myelodysplastic Syndromes Explained: Causes, Symptoms, and Disease Progression

Myelodysplastic syndromes (MDS) are a group of diverse bone marrow disorders characterized by the body's ineffective production of blood cells. At the core of MDS is a disruption in hematopoiesis—the process by which the bone marrow generates red blood cells, white blood cells, and platelets. Despite an overproduction of immature or abnormal cells within the marrow, the peripheral bloodstream often shows dangerously low levels of all blood cell types, a condition known as cytopenia.

Understanding the Biological Mechanisms Behind MDS

Scientists believe that genetic mutations and chromosomal abnormalities play a significant role in the development of myelodysplastic syndromes. Common alterations include deletions in chromosome 5 or 7, or trisomy 8, which interfere with normal cell maturation. These mutations cause hematopoietic stem cells to produce dysfunctional blood cells that die prematurely, leading to chronic fatigue and increased susceptibility to infections and bleeding.

Age as a Major Risk Factor

MDS primarily affects older adults, with most cases diagnosed in individuals over the age of 60. While it can occur at any age, the risk increases significantly with aging due to accumulated DNA damage and reduced efficiency in cellular repair mechanisms. Environmental exposures such as benzene, prior chemotherapy, or radiation therapy also elevate the likelihood of developing MDS.

Common Clinical Manifestations of Myelodysplastic Syndromes

The symptoms of MDS are largely tied to the specific type of blood cell deficiency present. Anemia—resulting from a shortage of red blood cells—is one of the most prevalent issues. Patients frequently report persistent fatigue, shortness of breath, chest tightness, and reduced stamina during routine activities. These signs stem from the body's inability to deliver sufficient oxygen to tissues and organs.

Bleeding and Bruising Due to Low Platelet Counts

Thrombocytopenia, or low platelet levels, makes even minor injuries potentially dangerous. Affected individuals may experience spontaneous nosebleeds, bleeding gums, oral mucosal blood blisters, or petechiae—small red or purple spots on the skin caused by capillary leakage. In severe cases, life-threatening hemorrhages can occur, including retinal bleeding that leads to blurred vision or partial vision loss.

Infections Linked to White Blood Cell Dysfunction

Neutropenia, a deficiency in functional white blood cells, compromises the immune system. As a result, patients are more vulnerable to bacterial, viral, and fungal infections. This often presents as recurrent fevers, accompanied by symptoms like cough, phlegm production, abdominal pain, or diarrhea. These infections may be prolonged and harder to treat due to impaired immune responses.

Potential Progression to Acute Leukemia

One of the most concerning aspects of MDS is its potential to transform into acute myeloid leukemia (AML). Approximately 30% of MDS cases progress to AML, especially those with high-risk genetic markers or severe bone marrow dysplasia. When this transformation occurs, patients may develop sudden worsening symptoms such as high fever, bone pain, unexplained weight loss, and widespread organ involvement typical of aggressive blood cancer.