Pediatric Charcot-Marie-Tooth disease (CMT)

What is pediatric Charcot-Marie-Tooth disease (CMT)?

Charcot-Marie-Tooth (CMT) disease is a neurological (nerve) disorder that causes a child to lose feeling and movement in their legs, feet, arms and hands. Sometimes this disease affects speech, breathing and swallowing.

With this condition, the peripheral nerves (the nerves outside the brain and spinal cord) don’t work properly. These nerves control muscles and sensations in the limbs, so children with CMT might experience problems with muscle movement and lack of feeling in their hands and feet.

CMT is typically inherited. This means it's caused by genes passed down through families. In rare cases, it can affect children with no family history of the disease.

In 1886 this disease was described by Dr. Jean-Martin Charcot and Pierre Marie (of France) and Howard Henry Tooth (of the UK).

Risk factors

It’s estimated that 1 in 2,500 Americans – and more than 2.5 million people worldwide – have CMT. The disease is also known as hereditary motor sensory neuropathy (HMSN) and peroneal muscular atrophy.

CMT affects boys and girls equally. The disease affects all genders and ethnicities.

What are the types and symptoms of pediatric Charcot-Marie-Tooth disease (CMT)]?

CMT is grouped into types based on symptoms, a child’s age, when symptoms appear and findings from genetic (blood) tests.

CMT types and symptoms include:

Type 1 CMT

As many as two out of three children with the disease have Type 1 CMT (also called demyelinating CMT). Symptoms appear during childhood and tend to affect the upper and/or lower limbs. Over time, a child may experience hearing loss.

Other symptoms of Type 1 CMT include:

• Cold hands and feet
• Loss of sensation in hands and feet
• Muscle cramps in the upper or lower limbs
• Numbness, tingling or burning sensation in the limbs
• Frequent falls
• Low muscle tone (hypotonia)
• Problems with balance and coordination, including walking
• High arches in the feet or no arch (flatfoot) 
• Hammertoes (toes that curl toward the bottom of the foot)
• Weak leg muscles that cause foot drop (inability to raise the front part of the foot while walking)

Type 2 CMT

Signs of Type 2 CMT tend to appear during the teenage years but can also be found younger children. The symptoms are similar to Type 1 CMT. Type 2 CMT may also affect a child’s ability to speak, swallow and breathe.

Type 3 CMT (Dejerine-Sottas syndrome)

CMT3, or Type 3, is apparent at birth. This rare form can cause severe symptoms that gradually get worse. A child with CMT3 may develop scoliosis (curved spine) and may not be able to walk. CMT3 is also called early-onset CMT and Dejerine-Sottas syndrome.

Other symptoms of Type 3 CMT include:

• Difficulty breathing and swallowing
• Low muscle tone (hypotonia)

Type 4 CMT

Type 4 CMT is very rare. The disease may be evident at birth or symptoms may develop during childhood. Children with this type of CMT gradually lose muscle strength. They may be unable to walk by the time they reach they are teenagers. These children are also at risk for hearing loss.

How is pediatric Charcot-Marie-Tooth disease (CMT) diagnosed?

Genetic testing

Our pediatric neurologists are among the most experienced CMT disease specialists in Texas and the surrounding states. We often can diagnose a child based on symptoms and family history of the disease.

Sometimes, our expert medical geneticists perform a simple blood test (genetic test) to confirm the diagnosis.

Nerve conduction velocity test

If genetic testing doesn’t identify a CMT-related gene change, we may perform nerve conduction velocity tests. This test helps us diagnose problems with nerves by measuring how fast electrical impulses travel through them to reach other parts of the body.

What causes pediatric Charcot-Marie-Tooth disease (CMT)?

A change in a gene (genetic mutation) causes CMT. A child inherits this gene change from a parent. There are more than 100 gene changes linked to CMT. These changes damage cells in peripheral nerves that help a child control and move muscles.

Rarely, a child with no family history of CMT develops the disease. This is the result of a new (spontaneous) gene change. Experts are still trying to determine why some children develop this new gene mutation. Once a child has this altered gene, they can pass it on to future generations.

How is pediatric Charcot-Marie-Tooth disease (CMT) treated?

As the only CMTA Center of Excellence for children in a span of six states, Children’s Health offers one of the region’s most comprehensive care programs. We bring together all the specialists your child needs to live a full life.

Rehabilitation services

Specialists in our Physical Medicine and Rehabilitation Services Program have deep experience working with children who have CMT. We show your child and you how to perform exercises at home that stretch and strengthen muscles. These exercises can help ease pain and improve a child’s flexibility and mobility. We can also help if your child needs orthotics (special shoe inserts or braces) or assistive devices like wheelchairs.

Depending on symptoms, your child may benefit from:

• Occupational therapy (OT)
• Physical therapy (PT)
• Speech therapy

Pain management

We offer a holistic approach to pain management. This means we focus on finding ways to make your child comfortable without using strong pain medicines. We’ll show you and your child how to massage tight muscles using infused oils that help ease pain.

When needed, we introduce pain medicines and engage the services of our pediatric pain specialists.

Gene therapies

Children’s Health is one of two pediatric medical centers in the country taking part in a clinical trial that will help us find new therapies for children with a very rare subtype of CMT called Type 4J. Children with Type 4J CMT rapidly lose their ability to walk, talk and breathe on their own.

A child with Type 4J who qualifies for the clinical trial may benefit from new gene therapies still in development. Gene therapies correct or replace the faulty gene that causes the disease. The treatment may stop or slow disease progression.

Nationwide treatment

Families nationwide have access to these promising investigational treatments through our Neurogenetics Disorders Program. We’re among a handful of pediatric centers in the country focused on developing gene therapies for children with neurological disorders.