Inborn errors of metabolism: iron.

The iron content of the body is normally closely regulated. Despite this, iron deficiency anaemia is common in women because iron losses due to menstruation and childbirth are not always compensated for by iron absorption from the diet. The role of transferrin in delivering iron to cells and of ferritin in storing iron within cells is well understood but the proteins involved in iron transport across membranes are only now being investigated. Relatively few genetic disorders affecting iron metabolism are known and most are rare. This paper briefly describes pyridoxine responsive sideroblastic anaemia, hyperferritinaemia-cataract syndrome, atransferrinaemia and genetic haemochromatosis. Rather than rare, the latter is one of the most common inherited disorders in northern European populations. Mutations in genes regulating membrane iron transport causing simple iron deficiency have not yet been described.