Charcot-Marie-Tooth disease- Type 2I
Overview
Charcot-Marie-Tooth disease, type 2: A rare inherited disorder characterized by abnormalities in the axon of the peripheral nerve cells instead of the myelin sheath coating of the nerves. The condition manifests as muscle weakness and wasting that usually starts in the legs and spreads to the hands and other parts of the body. The severity, age of onset and rate of progression of the condition varies depending on the genetic origin of the defect.
Symptoms
Symptoms usually begin in late childhood or early adulthood. Usually, the initial symptom is foot drop 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" or "inverted bottle" appearance. Weakness in the hands and forearms occurs in many people later in life as the disease progresses.
Causes
A definitive diagnosis for a specific type of CMT is established via genetic testing for most types. However, some genetic markers have not yet been identified, and a diagnosis can also be established via an electromyography examination (which shows that the velocity of nerve impulse conduction is decreased and the time required to charge the nerve is increased) and nerve biopsy.
Diagnosis
A definitive diagnosis for a specific type of CMT is established via genetic testing for most types. However, some genetic markers have not yet been identified, and a diagnosis can also be established via an electromyography examination (which shows that the velocity of nerve impulse conduction is decreased and the time required to charge the nerve is increased) and nerve biopsy.