Even though the development of the membrane abnormalities in sickle cell erythrocytes is due to the presence of a mutant gene product, sickle cell anaemia is in a sense a membrane disease. In particular, the presence of iron-containing breakdown products of haemoglobin in the sickle cell membranes provides a source of continued oxidative damage. An understanding of the primary causes of these membrane abnormalities may be useful in the development of effective therapies