Charcot-Marie-Tooth disease

What is Charcot-Marie-Tooth disease?

Charcot-Marie-Tooth disease (CMT) is a group of inherited genetic conditions that affect how the peripheral nerves work. These are the nerves outside the main central nervous system, i.e. the brain and spinal cord.

Some mutations directly damage the nerves, while others harm the myelin sheath, the protective layer around them. In both cases, the signals travelling to and from the feet, legs, hands, and arms become weaker.

In the long term, this causes nerve damage, leading to muscle weakness and numbness. Charcot-Marie-Tooth disease is progressive, although it does not affect life span.

Symptoms

Charcot-Marie-Tooth disease symptoms may include:

• drop foot (foot drop)
• foot deformity (high-arched feet)
• curled toes (hammer toes)
• loss of muscle in the lower leg
• numbness in the feet
• difficulty with balance

Later on, similar symptoms may also appear in the arms and hands.

In the most common kinds of Charcot-Marie-Tooth disease, symptoms usually begin before the age of 20.

Causes

CMT is caused by a mutation in one of the many genes responsible for the development of the peripheral nerves. There’s no single faulty gene that causes it. Different gene mutations cause different types of CMT and these can be inherited in different ways.

Why proper management of CMT matters

Without early intervention, CMT can lead to:

• progressive foot deformities (pes cavus, hammer toes, ankle instability)
• increased fall risk due to foot drop and poor balance
• joint pain and strain from compensatory walking patterns
• loss of mobility and independence over time

Treatment

While there’s no cure for CMT, therapies, treatments and orthotics can help maintain function, prevent deformities, improve mobility, manage symptoms and enhance independence and quality of life.

• Ankle Foot Orthoses (AFOs): prevent drop foot, improve stability, and reduce tripping risk
• custom insoles: provide arch support, correct weight distribution, and relieve pressure points
• supportive footwear: stabilise the ankle, accommodate foot deformities, and improve comfort
• Knee-Ankle-Foot Orthoses (KAFOs) (in severe cases): control knee hyperextension and improve walking efficiency

See our CMT treatment page