Ineffective Erythropoiesis with Morphologically Abnormal Erythroblasts and Unconjugated Hyperbilirubinaemia

Summary. Four cases of congenital dyserythropoietic anaemia in two families are described. The evidence for a dyserythropoietic state is discussed and the suggestion made that the hyperbilirubinaemia of the unconjugated type is mainly due to intramedullary bilirubin formation. Many abnormal multinucleated erythroblasts were found in the bone marrow. The evidence for a membrane defect and a possible haemoglobin abnormality have been presented.