Congenital dyserythropoietic anemia (CDA) is an autosomal recessive disorder that affects erythropoiesis. Due to dyserythropoiesis (abnormal red blood cell production), erythroblasts (immature red blood cells) present in patients with CDA has an odd shape and extra nuclei that cannot develop into functional normal red blood cells. The clinical features of CDA include fatigue, weakness, pale skin, and further complications. CDA consists of three main forms: type I, type II, and type III. CDA type II varies between mild to severe and the majority of patients suffer from jaundice, hepatosplenomegaly, and gallstones. It is generally diagnosed throughout childhood or adolescence. The abnormal iron overload usually takes place following the age of 20 years, inducing complications comprising diabetes, heart disease, and cirrhosis. CDA type II is known to be the most common form of the disease, with over 300 reported cases.

Congenital dyserythropoietic anemia (CDA) type II is associated with mutations in the SEC23B (Sec23 homolog B) gene, which encodes a protein that regulates intracellular proteins transportation.