Diagnosis and management of congenital haemolytic anaemia.

Congenital haemolytic anaemias are hereditary conditions resulting from an increase in the rate of red cell destruction.1 Four main types of red cell abnormality can cause haemolysis: • cytoskeletal membrane disorders (eg hereditary spherocytosis (HS), hereditary elliptocytosis (HE), hereditary pyropoikilocytosis (HPP)) • disorders of membrane cation transport (eg hereditary stomatocytosis) • enzyme deficiencies (eg dehydrogenase (G6PD) deficiency, pyruvate kinase (PK) deficiency) • disorders of haemoglobin synthesis (eg sickle cell anaemia, unstable haemoglobins). Congenital haemolytic anaemia can also be a feature of more generalised metabolic problems not directly involving the red cells such as lipid abnormalities (eg abetalipoproteinaemia, sitosterolaemia) and Wilson’s disease. Although most thalassaemia syndromes involve an element of haemolysis, the predominant defect is ineffective erythropoiesis and the former will not be considered further in this article.