congenital dyserythropoietic anemia type iv congenital dyserythropoietic anemia type iv congenital dyserythropoietic anemia type iv (cda iv) has been described with typical morphologic features of cda ii but a negative acidified-serum test. congenital dyserythropoietic anemia type ivspecialtyhematology presentation cda type iv is characterized by mild to moderate splenomegaly. hemoglobin is very low and patients are transfusion dependent. mcv is normal or mildly elevated. erythropoiesis is normoblastic or mildly to moderately megaloblastic. nonspecific erythroblast dysplasia is present. genetics congenital dyserythropoietic anemia type iv is an autosomal dominant inherited red blood cell disorder characterized by ineffective erythropoiesis and hemolysis resulting in anemia. circulating erythroblasts and erythroblasts in the bone marrow show various morphologic abnormalities. affected individuals with cdan4 also have increased levels of fetal hemoglobin. type omim gene locus cdan4 613673 klf1 19p13.13-p13.12 treatment treatment consists of frequent blood transfusions and chelation therapy. potential cures include bone marrow transplantation and gene therapy.