What characterizes myelodysplastic syndrome?

Myelodysplastic syndrome (MDS) is characterized by ineffective hematopoiesis, leading to an inability of blood cells to properly mature and function. This results in a variety of blood cell lineages showing abnormal morphology and deficiencies in the number of mature cells. Specifically, this syndrome often involves arrests or delays in the maturation process of red blood cells, white blood cells, and platelets.

Within this context, the correct answer highlights the critical feature of MDS: the failure of hematopoietic progenitor cells to mature into fully functional blood cells, which contributes to the anemias, leukopenias, and thrombocytopenias commonly observed in affected individuals.

Other options reflect different hematological conditions. Increased white blood cell production or increased platelet count is not typical of MDS, as the syndrome generally leads to cytopenias rather than overproduction of cells. The reticulocyte production index, which measures the responsiveness of the bone marrow in producing new red blood cells, would typically be low in cases of MDS due to ineffective erythropoiesis, rather than a higher index like 2.5, which indicates a compensatory response to anemia. This distinction underscores why the arrest in maturation of all blood cells is