Congential dyserythropoietic anemia--type IV.

Congenital dyserythropoietic anemia is characterized by ineffective erythropoiesis and increased numbers of multinucleated red cell precursors in the marrow. This syndrome has been subclassified on the basis of morphologic differences in the red cell precursors. Type I is characterized by megaloblastoid erythropoiesis and macrocytosis; Type II, by normoblastic multinuclearity and normocytosis; and Type III, by frequent giant multinucleated erythroblasts and macrocytes.