An introduction to the molecular basis of inherited myelin diseases.

The myelin sheath is an extension of a plasma membrane tightly wrapped around axons. It facilitates conduction while conserving space and energy. Myelin is characterized by a high lipid content (80% of dry weight). Most myelin proteins are unique to that structure and some of them are restricted to the central or peripheral nervous system. In this review a few examples of inherited metabolic disorders affecting the oligodendrocyte and/or the Schwann cells are presented. Emphasis is placed on mutations in animals that represent invaluable models for investigating the molecular mechanisms of inherited myelin diseases in humans.