Illuminating Charcot-Marie-Tooth disease

Charcot-Marie-Tooth Disease (CMT) is a group of hereditary disorders characterized by sensory loss, muscle weakness and atrophy.1 As a result of damage to peripheral nerve axons and the myelin surrounding them, nerve cells of individuals with CMT are unable to properly send electrical signals to motor nerves and sensory peripheral nerves.2

CMT affects approximately 126,000 individuals in the USA and 2.6 to 3 million people worldwide.2,3 More than 40 gene mutations are known to cause the clinical symptoms associated with CMT, with several other yet-to-be identified mutations.1,2 There are several different subtypes of CMT, and it is possible for individuals to be diagnosed with multiple subtypes if they have more than one mutation. However, more than 50% of CMT cases are caused a duplication of the PMP22 gene on chromosome 17.

The onset of the disease can begin at any age, but progressive muscle weakness is often noticed in adolescence or early adulthood. Symptoms generally begin in the lower legs and feet before spreading to the arms, hands, and fingers. Muscle weakness or paralysis, foot deformities, and difficulty with fine motor skills are all characteristics of the disease. In some rare cases, breathing difficulties may occur when the muscles of the diaphragm are affected.1,2