Hereditary Disorders of the Red Cell Membrane and Disorders of Red Cell Metabolism

Inherited disorders affecting the red cell membrane and metabolism result in shorter red cell survival and congenital haemolytic anaemia of variable severity. Defects of membrane proteins cause abnormal red cell morphology. The mutations responsible for these defects are many and heterogeneous, and result in hereditary spherocytosis, hereditary elliptocytosis/pyropoikilocytosis, Southeast Asian ovalocytosis, and hereditary stomatocytosis. The main metabolic pathways in red cell are the anaerobic glycolysis, the hexose monophosphate shunt, the glutathione cycle, and nucleotide metabolism. They produce ATP as the only source of energy and reducing power to maintain haemoglobin in its functional state and to counteract oxidative stresses. The most common enzymopathies are deficiencies of glucose-6-phosphate dehydrogenase and pyruvate kinase, however, there are a number of other very rare enzyme disorders. When the defective enzyme is expressed throughout the body, non hematological symptoms may also occur.