Congenital dyserythropoietic anemias (CDAs) are primarily characterized by which feature?

Congenital dyserythropoietic anemias (CDAs) are primarily characterized by the presence of bizarre multinucleated erythroblasts. These multinucleated erythroblasts are a hallmark feature of the disorder and reflect the abnormal erythropoiesis that occurs in CDAs. The genetic defects associated with these anemias lead to ineffective erythropoiesis, which can manifest as a variety of morphological abnormalities in the erythroblasts during their development in the bone marrow.

In CDAs, the abnormal maturation of erythrocyte precursors typically results in these distinctive erythroblast forms that can be identified on a bone marrow smear. This finding is crucial for proper diagnosis and understanding of the underlying pathology of congenital dyserythropoietic anemias.

Other options describe characteristics that may be found in different hematological conditions. For instance, cytogenetic disorders involve genetic abnormalities that are not specific to CDAs and may not present with the distinctive appearance of erythroblasts. Similarly, megaloblastic erythropoiesis typically implies a deficiency in vitamin B12 or folate and is characterized by larger-than-normal red cell precursors, rather than multinucleation. An