What is Charcot-Marie-Tooth disease?
Charcot-Marie-Tooth disease, also called CMT, is a group of genetic disorders that affect the peripheral nerves. These are the nerves outside of central nervous system (which is the brain and spinal cord). The peripheral nerves carry messages from the brain to muscles and sensory cells throughout the body. CMT affects both motor and sensory nerves. Motor nerves cause muscles to contract and allow people to perform voluntary tasks like walking or talking. Sensory nerves have cells, or receptors, that respond to stimuli and send information to the brain. For example, in the skin they respond to touch, pressure, vibration, temperature, and pain. The most common symptoms of CMT happen because the peripheral nerves don't function properly. These symptoms include slow degeneration of muscles in the feet and legs causing muscle weakness and muscle cramps. There may also be a mild loss of sensation in the feet and legs. The specific symptoms can differ among people with this disorder; this is even true for people in the same family. Some people never even realize they have the disorder, while others may have some moderate disability due to symptoms. There can be very severe symptoms in some people. Most people have some symptoms, but life expectancy is usually not reduced by having CMT. The symptoms will get worse, although usually very slowly. As the disease progresses, people may begin to sprain their ankles a lot, trip and fall a lot, and they may have a high arch to the bottom of their feet, or toes that bend upward at the middle joint (hammertoes). Often, the hands will become involved, leading to muscle weakness in the hands. This can cause problems with daily tasks like turning doorknobs or fastening buttons. Some people experience pain and fatigue as well. Rare forms of CMT may cause more severe symptoms and affect other systems of the body. Symptoms usually begin in the teens or early adulthood, but can also start years later or earlier. There are many different forms of CMT and changes (mutations) in one of many different genes can cause these disorders. There is no cure, but there are a variety of treatments to help manage the symptoms.
Learning About Charcot-Marie-Tooth Disease. The National Human Genome Research website. https://www.genome.gov/11009201/learning-about-charcotmarietooth-disease/
Charcot-Marie-Tooth disease. Genetics Home Reference website. https://ghr.nlm.nih.gov/condition/charcot-marie-tooth-disease
Charcot-Marie-Tooth disease. The National Organization for Rare Diseases website. https://rarediseases.org/rare-diseases/charcot-marie-tooth-disease/
Charcot-Marie-Tooth Disease Fact Sheet. The National Institute of Neurological Disorders and Stroke website. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Charcot-Marie-Tooth-Disease-Fact-Sheet
Cruse RP. Hereditary primary motor sensory neuropathies, including Charcot-Marie-Tooth disease. UpToDate, Inc. website. http://www.uptodate.com/contents/hereditary-primary-motor-sensory-neuropathies-including-charcot-marie-tooth-disease