The prevalence of CMT is 1 per 2,500 population, which results in 125,000 patients in USA, making CMT the most common inherited neurological disease. Because CMT is an inherited disorder, patients almost always have a family history of the disease. There are, however, rare sporadic cases without a family history, which likely represent spontaneous mutations. There does not appear to be any racial predominance. Clinical Features CMT is characterized by slowly progressive weakness beginning in the distal limb muscles, and typically in the legs before the arms.
Symptoms usually appear in the first two decades of life.
Patients may first complain of difficulty walking, especially with tripping due to foot and distal leg weakness. Ankle sprains are common in this stage. In its subtlest manifestation, patients may only note clumsiness with running or simply being not very athletic. Intrinsic foot muscle weakness commonly results in the foot deformity known as pes cavis. Weakness in the upper extremities usually develops later than the lower extremities.