Causes of Myelodysplastic syndrome
Myelodysplastic syndrome is an umbrella term, and its causes depend on each subtype or modality. There are three main genetic profiles in myelodysplastic syndrome. Patients can have a completely normal genetic profile, a slight and balanced chromosomal abnormality, or complex and mounting abnormalities consisting of 3 or more mutations.
When patients acquire a myelodysplastic syndrome as a result of aggressive cancer therapy, their chances of complex mutations are 50%. These patients have a worse prognosis and usually have more severe symptoms that may not respond successfully to treatment.
Myelodysplastic syndromes may also develop after the patient is exposed to certain chemicals, especially benzene, insecticides, fungicides, weed killers and other agricultural products. In some cases, viral infections can be an initial trigger in some patients. And even though heredity might be a risk factor because some familial incidences have been described, they are not the main cause of myelodysplastic syndromes.
Although rare, hereditary causes have been described, especially through mutations in the RUNX1 gene or the GATA2 gene. Another cause that has been described but not thoroughly investigated is a chronic immune stimulation in cases of treatment for autoimmune conditions, which is especially prevalent in genetically predisposed patients.