Symptoms:

Symptoms usually begin between mid-childhood and early adulthood. They may include:

• Foot drop (inability to hold foot horizontal)
• Foot deformity (very high arch to feet)
• Loss of lower leg muscle, which leads to skinny calves
• Numbness in the foot or leg
• "Slapping" gait (feet hit the floor hard when walking)
• Weakness of the hips, legs, or feet

Later, similar symptoms may appear in the arms and hands, which may include a claw-like hand deformity.

Signs and tests:

A physical exam may show thickened nerve bundles under the skin of the legs. The stretch reflexes in the legs are absent. There is loss of muscle control and atrophy in the foot or leg. Lifting up the foot and toe-out movements will be difficult.

A muscle biopsy or nerve biopsy may confirm the diagnosis. Nerve conduction tests are often done to tell the difference between different forms of the disorder.

Genetic testing is available for most forms of the disease.