Definition of Charcot-Marie-Tooth disease:

Charcot-Marie-Tooth disease is a group of disorders that affect the peripheral nerves, the nerves running from outside the brain and spine.

Causes, incidence, and risk factors:

Charcot-Marie-Tooth is one of the most common inherited nerve-related disorders. Defects in at least 14 genes cause different forms of this disease.

The disease involves damage to the covering (myelin sheath) around nerve fibers. In some, the disease causes destruction of the myelin sheath. In others, the central (axon) portion of the nerve cell wears away.

Nerves that stimulate movement (the motor nerves) are most severely affected. The nerves in the legs are affected first and most severely.