The diagnostic challenge of congenital dyserythropoietic anaemia: two cases of 'CDA type II'.

The congenital dyserythropoietic anaemias (CDAs) are a group of rare hereditary disorders characterised by ineffective erythropoiesis and morphological abnormalities in the erythroblasts. Patients may present with jaundice or with symptoms of anaemia, gall stones or iron overload. The diagnosis can be challenging and cases have been confused with haemolytic anaemia, haemochromatosis or a haemoglobinopathy. A delayed diagnosis can lead to inappropriate treatment or delayed management of iron overload. We present two patients previously diagnosed as CDA type II in whom the diagnosis was revised to CDA type I and to hereditary spherocytosis. The conditions are compared and the approach to diagnosis is discussed.