Charcot-Marie-Tooth Disease
Overview
Plain-Language Overview
Charcot-Marie-Tooth Disease is a group of inherited disorders that affect the peripheral nerves, which are responsible for movement and sensation in the limbs. It primarily causes muscle weakness and wasting in the feet, legs, and sometimes hands, leading to difficulties with walking and balance. The condition involves damage to the myelin sheath or the nerve axon itself, disrupting nerve signal transmission. Symptoms often begin in adolescence or early adulthood and progress slowly over time. People with this disease may also experience sensory loss and foot deformities such as high arches or hammertoes.
Clinical Definition
Charcot-Marie-Tooth Disease (CMT) is a hereditary peripheral neuropathy characterized by progressive demyelination or axonal degeneration of peripheral nerves. It is most commonly caused by mutations in genes such as PMP22, MPZ, and GJB1, leading to defective myelin sheath formation or axonal transport. The disease manifests with distal muscle weakness, atrophy, and sensory loss, predominantly affecting the lower extremities. CMT is classified into types based on electrophysiological and genetic findings, with CMT1 involving demyelination and CMT2 involving axonal loss. The condition results in impaired motor and sensory nerve conduction velocities and is a major cause of inherited neuropathy worldwide. Clinical significance includes progressive disability due to muscle weakness and sensory deficits, often accompanied by skeletal deformities.