Myelodysplastic syndrome is a rare, heterogenous type of blood disorder that affects normal blood cell production in the bone marrow. Consequently,

the bone marrow fails to produce properly functioning blood cells, producing instead abnormal, immature blood cells (blast cells).

Mostly, the causes of MDS remain unknown, however different factors such as genetics and environment may play a role. MDS occurs due to a mutation in one or more genes that control blood cell development. Secondary MDS may develop after autoimmune disorders or cancer treatment involving chemotherapy and radiation therapy. Due to the lack of normal blood cell production (red cells, white cells and platelets) people may experience fatigue, dizziness, weakness, pale skin colour, bruising and bleeding, susceptibility to infections and headaches. MDS is predominantly a disease of the elderly (>60 years), affecting men slightly more often than women. MDS can be classified into several subtypes according to the type and number of blast cells in the bone marrow. The different subtypes vary in severity. For some individuals, MDS may become a progressive life-threatening disease. Approximately 30% of MDS patients will progress to form acute myeloid leukemia (AML). Using the Revised International Prognostic Scoring System (IPSS-R) MDS patients may be classified into risk groups by assessing mortality and progression to AML. For this reason, MDS is sometimes referred to as pre-leukemic disorder. Treatment of MDS depends on several factors such as the exact type of MDS, the age, general health and risk status of the patient. The major treatment option is supportive care with antibiotics and blood transfusions, with the aim to treat possible complications that may arise from the disease. In severe and progressive cases, chemotherapy is administered to control the rising blast cell count, also in combination with other therapeutic agents. In some cases, stem cell transplantation may be an option.

Source: rarediseases.org; leukemia.org; Ghulam J. Mufti et al., ABC of Clinical Haemotology (2018)