[Molecular pathology of the erythrocyte membrane]

The erythrocyte membrane, in the broad sense of the term, comprises a lipid bilayer and below it the erythrocyte skeleton responsible for the mechanical properties of red cells. The lipid bilayer contains numerous proteins including the anion transporter. The underlying portion contains spectrin, actin and protein 4.1. At the interface between these two portions, ankyrin, protein 4.2 and other proteins are found. The structure and mode of expression of the corresponding genes are roughly known, as are the structure-function relationships within the proteins. In the wake, or sometimes ahead of these fundamental advances, dramatic strides have been made in the molecular pathology of the erythrocyte membrane. Hereditary spherocytosis results from mutations altering on ankyrin, the anion transporter or protein 4.2, while elliptocytosis results from mutations affecting spectrin or protein 4.1. Thus, the knowledge already acquired makes it possible to diagnose, at molecular scale, not only hereditary spherocytosis and elliptocytosis, but also several other genetic diseases of the erythrocyte membrane.