Charcot-Marie-Tooth Disease Support Group

Charcot-Marie-Tooth disease, also known as Hereditary Motor and Sensory Neuropathy (HMSN) or Peroneal Muscular Atrophy, is a heterogeneous inherited disorder of nerves (neuropathy) that is characterized by loss of muscle tissue and touch sensation, predominantly in the feet and legs but also in the hands and arms in the advanced stages of disease. Though presently incurable, this disease is one of the most common inherited neurological disorders, with 36 in 100,000 affected (Krajewski et al.,2000).

The disorder is caused by the absence of molecules that are essential for normal function of the nerves due to deficiencies in the structure of the genes coding these molecules. The absence of these chemical substances gives rise to dysfunction either in the axon or the myelin sheath of the nerve cell.

Symptoms usually begin in late childhood or early adulthood. Usually, the initial symptom is foot drop due to involvement of the peroneal nerve, which is responsible for raising the feet, early in the course of the disease. This can also cause hammer toe, where the toes are always curled. Wasting of muscle tissue of the lower parts of the legs may give rise to "stork leg" appearance. Weakness in the hands and forearms occurs in many people later in life as the disease progresses. Symptoms and progression of the disease can vary. Breathing can be affected in some; so can hearing, vision, and the neck and shoulder muscles. Scoliosis is common. Hip sockets can be malformed. Gastrointestinal problems can be part of CMT, as can chewing, swallowing, and speaking (as vocal cords atrophy). A tremor can develop as muscles waste. Pregnancy has been known to exacerbate CMT, as well as extreme emotional stress.