Authors: Mekka Garcia, MD, NYU Grossman School of Medicine
Alison L. Christy, MD, PhD, Providence Pediatric Neurology at St. Vincent Medical Center—Portland, Oregon
Reviewed: July 2022
SUMMARY
Charcot-Marie-Tooth disease (CMT) is a group of inherited disorders of the nerves. It is one of the most common causes of damage to the peripheral nerves worldwide. It is due to genetic variations that affect the structure of the nerve.
There are four major types of CMT. They have similar symptoms. However, they differ in the age of onset and gene variations.
Most commonly, people with CMT experience weakness and numbness. It starts in the toes and feet and progresses up through the body. There is no cure for CMT, but supportive care is available.
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Disorder Overview
DESCRIPTION
The nerves of the body are like electrical wires. The wire itself is called the axon. The outside coating is called myelin. Electricity travels down the wires from the brain to the muscle. It communicates sensation back to the brain.
Some nerves allow you to feel (sensory nerves). Others allow you to move (motor nerves).
The set of nerves that travel from the spinal column to the muscles is called the peripheral nervous system. In the most common type of CMT, the myelin of the motor and sensory nerves breaks down. Other types of CMT affect the axon of the nerves. This means the brain and muscle cannot communicate well, affecting sensation and movement.
SIGNS AND SYMPTOMS
Usually, CMT begins with changes in sensation and weakness in the feet and legs. It slowly progresses to the rest of the body over the course of many years.
Other symptoms include:
- Foot deformities including pes cavus (high arch) and hammer toes (bent toes)
- Foot drop (difficulty lifting foot when walking)
- Loss of hand and feet muscles
- Changes in sensation including numbness, tingling, burning, and pain
- Scoliosis (curved spine)
- Optic atrophy (decrease in size of optic nerve)
- Hearing loss
- Brain and spinal cord abnormalities including loss of volume
CAUSES
CMT disease is an inherited disorder. It is inherited either from the child’s mother or father. There are several ways to inherit the disease, depending on the type of CMT. The types of CMT include:
CMT1A
- CMT1A is the most common type of CMT.
- Symptoms usually occur during the first ten years of life.
- CMT1A is caused by variation in genes that affect the myelin coating around the nerve.
- CMT1A is inherited in an autosomal dominant manner. This means that if either parent has one gene variation, there is a 50% chance that their children will inherit the disease.
- The most severe form of CMT1A is called Roussy-Levy syndrome. Symptoms occur during infancy or early childhood.
CMT1B
CMTX1
- CMTX1 is the second most common form of CMT.
- CMTX1 is caused by variation in genes that affect the axon of the nerve.
- CMTX1 is inherited in an X-linked dominant manner.
- Humans have two sex chromosomes: the X and Y chromosomes. Females usually have two X chromosomes (XX). Males usually have one X and one Y chromosome (XY). The mutated gene in CMTX1 is located on the X chromosome.
- Because CMTX1 is dominant, it can be passed from the mother or father, and can affect people with either XX or XY chromosomes. This condition is more common when people have XY chromosomes.
- Symptoms are mild to moderate.
CMT2A
LABORATORY INVESTIGATIONS
CMT can be diagnosed by taking a careful health and family history and doing a complete physical exam. Tests that may help confirm the diagnosis include:
- Genetic testing. This tests for the presence of mutations (variation) in genes important for nerve structure.
- Nerve conduction study. This electrical stimulation test evaluates nerve response. It is used to confirm a nerve disorder and assess its severity.
- Nerve biopsy. This evaluates the structure of a nerve. It is used to confirm a nerve disorder and identify severity of damage.
TREATMENT AND THERAPIES
Since there is no cure for CMT disease, therapies are aimed at symptomatic and supportive care. Some of these therapies include:
Non-steroidal anti-inflammatory drugs (NSAIDs).
Treatments for neuropathic pain.
Orthoses and walking aids.
Back bracing and/or surgery.
OUTLOOK
CMT is a progressive disease. This means symptoms usually worsen over time. Most people with CMT live to adulthood. However, they may experience disability from the condition.
People with CMT may suffer from complications such as:
- Injuries from falls
- Difficulty walking
- Pain
- Skin/bone infections
- Injuries due to changes in sensation (such as lack of pain)
- Breathing problems
RELATED DISORDERS
- Hereditary sensory and autonomic neuropathy
- Distal hereditary motor neuropathy
Resources
Charcot-Marie-Tooth Association
The vision of the Charcot-Marie-Tooth Association (CMTA) has always been “A World Without CMT” and they aim to accomplish this mission by accelerating research and empowering patients. CMTA is devoted to:
- Driving the development of new drugs to treat CMT
- Meeting the needs of patients with CMT
- Accelerating research for a cure
CMTA is the driving force behind CMT research and CMT community programs. They have 36 CMTA Centers of Excellence in the US and four overseas. The CMTA community includes patients, families, and supportive friends—along with hundreds of experts in neurology, genetics, orthopedic surgery, physiatry, physical therapy and podiatry—all committed to the CMTA vision. CMTA offers a place to get connected to other youth with CMT and to learn all about their programs on the CMTA Youth Program page. The Charcot-Marie-Tooth Association also hosts a private Facebook group with over 17,000 members.
The European Charcot-Marie-Tooth Federation
The European Charcot-Marie-Tooth Federation (ECMTF) is a non-profit organization registered in Belgium, formed by European national associations supporting people affected by Charcot-Marie-Tooth or similar diseases. They represent about 1/3 of people suffering from Charcot-Marie-Tooth disease in Europe, which is about 100,000 patients. ECMTF’s main objectives are to support research and clinical trials on CMT and to raise awareness on this rare and little-known disease. Collaboration and communication with other CMT organizations and charities allow ECMTF to share expertise and best practice for supporting the CMT community.
Muscular Dystrophy Association
Families are at the heart of Muscular Dystrophy Association’s mission. A caring and concerned group of families started MDA in 1950, and they continue to relentlessly pursue their promise to free families from the life-threatening effects of muscular dystrophy and muscle-debilitating diseases today. MDA focuses on over 43 neuromuscular diseases in children and adults, including Charcot-Marie-Tooth.
MDA empowers families with support by providing: A Resource List, Outside Organization Programs & Information, Summer Camp, Community Education, Community Events, and Young Adult Programs. MDA’s research program awards grants to the world’s best scientists investigating promising theories and therapies that may accelerate treatments and cures for families living with muscular dystrophy, ALS and related neuromuscular diseases.
Publications
JCN: What Your Pediatric Neurologist Wants You to Know: CMT
Podcast from SAGE Neuroscience and Neurology/Journal of Child Neurology (JCN). Dr. Geetanjali Rathore, Pediatric Neurologist, Associate Professor of Neurosciences and Clinical Director of the CMT clinic at the University of Nebraska discusses Charcot-Marie-Tooth disease.
JCN: What Your Pediatric Neurologist Wants You to Know
Podcast from SAGE Neuroscience and Neurology/Journal of Child Neurology (JCN). JCN’s Residents and Fellows Board Director, Dr. Alison Christy, interviews Dr. Farida Abid, Assistant Professor in Pediatric Neurology at Texas Children’s Hospital about Neuromuscular disease.
Child Neurology Foundation (CNF) solicits resources from the community to be included on this webpage through an application process. CNF reserves the right to remove entities at any time if information is deemed inappropriate or inconsistent with the mission, vision, and values of CNF.
Research
ClinicalTrials.gov for Charcot-Marie-Tooth (birth to 17 years).
These are clinical trials that are recruiting or will be recruiting. Updates are made daily, so you are encouraged to check back frequently.
ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world. This is a resource provided by the U.S. National Library of Medicine (NLM), which is an institute within the National Institutes of Health (NIH). Listing a study does not mean it has been evaluated by the U.S. Federal Government. Please read the NLM disclaimer for details.
Before participating in a study, you are encouraged to talk to your health care provider and learn about the risks and potential benefits.
Family Stories
The Charcot-Marie-Tooth Association shares stories of living with CMT on the My CMT Story page. You will find inspiration from children as well as adults.
The information in the CNF Child Neurology Disorder Directory is not intended to provide diagnosis, treatment, or medical advice and should not be considered a substitute for advice from a healthcare professional. Content provided is for informational purposes only. CNF is not responsible for actions taken based on the information included on this webpage. Please consult with a physician or other healthcare professional regarding any medical or health related diagnosis or treatment options.
References
CMT Research Foundation. Types of Charcot-Marie-Tooth [Internet]. Atlanta, GA: CMT Research Foundation. Available from: https://cmtrf.org/what-is-cmt-disease/types-of-cmt/
Jani-Acsadi A, Ounpuu S, Pierz K, Acsadi G. Pediatric Charcot-Marie-Tooth disease. Pediatr Clin North Am. 2015 Jun;62(3):767-86. https://doi.org/10.1016/j.pcl.2015.03.012. Epub 2015 Apr 15. PMID: 26022174.
Mayo Clinic Patient Care and Health Information. Charcot-Marie-Tooth disease [Internet]. Mayo Foundation for Medical Education and Research (MFMER). 2022. Available from: https://www.mayoclinic.org/diseases-conditions/charcot-marie-tooth-disease/symptoms-causes/syc-20350517
Morena J, Gupta A, Hoyle JC. Charcot-Marie-Tooth: From Molecules to Therapy. Int J Mol Sci. 2019 Jul 12;20(14):3419. https://doi.org/10.3390/ijms20143419. PMID: 31336816; PMCID: PMC6679156.
National Institute of Neurological Disorders and Stroke. Charcot-Marie-Tooth Fact Sheet [Internet]. Bethesda, MD: National Institutes of Health (NIH). 2022. Available from: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Charcot-Marie-Tooth-Disease-Fact-Sheet#3092_1