What Is Charcot-Marie-Tooth Disease?

Medically Reviewed by Christopher Melinosky, MD on May 06, 2023
Written by WebMD Editorial Contributors
4 min read

Charcot-Marie-Tooth Disease affects the nerves outside the spinal cord and brain. People with the condition can have problems with their feet and trouble balancing.

Three doctors -- Jean-Martin Charcot, Pierre Marie and Howard Henry Tooth – identified a nerve disease back in 1886. Today, a whole group of genetic disorders is named after that trio. Other names it is known by are hereditary motor and sensory neuropathy and peroneal muscular atrophy.

Researchers have found 90 genetic types of CMT disease. It affects roughly 1 in every 2,500 Americans.

You can get a number of treatments, including physical therapy, braces and other orthopedic devices, and surgery.

It isn't contagious. It’s passed down from parents to children in their DNA. The disease has no known cure, but scientists have identified many genes that cause the disorder.

Genetic mutations in CMT affect the way that nerve cells “talk” with each other. Over time, they’re unable to work properly and start to fall apart. This can make you become weak and possibly less able to feel sensations such as a blister on your toe.

The symptoms of CMT disease generally start before you’re out of your teens.

One that shows up a lot is a high arch, which happens as some foot muscles weaken while others remain strong. Another possible problem: hammertoes, in which the second, third or fourth toes bend in the middle. These can start making it hard to walk, and you tend to get blisters and calluses.

As walking gets harder, you may have a hard time lifting your feet (called “foot drop”). You may form a “slapping” gait, in which your foot slaps against the floor.

You might start to lose muscle in your lower legs. Numbness and problems with balance may set in.

Later, the condition may affect your hands and arms. Usually, that’s as far as it goes, and people can live long, full lives with CMT disease.

If you start showing symptoms, see your doctor. You’ll likely be referred to a neurologist, a specialist in the nervous system.

They’ll likely take a family history, look at your symptoms, get X-rays and do some tests. Among them:

  • Walking on your heels. This is a way to check for leg weakness.
  • Muscle-reflex exams. One example is the knee-jerk reflex. People with CMT disease often don’t respond to these basic tests.
  • The nerve conduction velocity test. A doctor attaches electrodes to your skin and gives your body mild shocks. This tests the ability of your nerves to send and receive messages. People with CMT have a slow or weak response.
  • Electromyography. The doctor sticks a narrow needle into a muscle to check for electrical activity as you do things such as make a fist.

In addition, your doctor may order a DNA blood test to see if you carry gene mutations for this condition. A negative test (which means one is not found) can’t rule out CMT disease because not every mutation has been identified.

There is no cure for CMT disease. You can manage it in a number of ways.

Foot care is important. Doctors urge people to regularly check their feet, keep their nails trimmed, and wear the right kind of shoes. Other things include:

  • Physical therapy. This involves working with a therapist to stretch and strengthen your muscles with low-impact activities such as swimming, biking, and aerobics. Doctors recommend starting early, before the muscles start to waste away.
  • Occupational therapy. If the disease has progressed to the arms and hands, CMT disease patients may find it hard to do everyday tasks. A specialist can train you to improve your strength, grip, and flexibility.
  • Assistive devices. Leg braces, custom footwear, and other orthotics can provide support and ease mobility.
  • Medication. Talk to your doctor about painkillers and other drugs that can ease the pain of muscle cramps or nerve damage.

In certain cases, your doctor may recommend surgery to repair foot and joint problems. However, the disease’s effects on the nervous system can’t be reversed.

You can also check into support groups, including the Charcot-Marie-Tooth Association and the Muscular Dystrophy Association.

Because of Charcot-Marie-Tooth’s effects on joints and movement, it can cause other problems:

  • Breathing and swallowing problems. If the muscles that control your diaphragm are affected, you may find yourself short of breath all the time. If this happens, see a doctor at once. There are medicines that can help treat this issue.
  • Infection. Because it may cause foot numbness, people sometimes ignore scrapes and wounds. Left untreated, they may lead to infection.
  • Hip dysplasia. Misalignment or poor development of the hips can be more pronounced with CMT.
  • Pregnancy risks. Women with CMT have a greater chance of complications when they’re expecting.