Blood, Immune, and Hematologic Disorders Comprehensive Practice Exam 2026

Myelodysplastic syndromes are linked most strongly to aging, prior DNA-damaging exposures, and inherited predispositions. Advanced age is the strongest risk factor because hematopoietic stem cells accumulate genetic errors over time, increasing the chance of dysplastic blood cell development. Treatments that damage the marrow, such as chemotherapy or radiation, can induce therapy-related MDS years later by causing lasting changes in stem cells. Genetic or congenital syndromes, including Down syndrome, confer a predisposition to abnormal hematopoiesis and higher risk of MDS. Other factors like smoking, viral infections, or early-life birth weight don’t have the same established association with MDS. So the combination of older age, history of cytotoxic therapy, and genetic syndromes best reflects the known risk factors.