Charcot-Marie-Tooth disease

Charcot-Marie-Tooth (CMT) disease is a genetic condition and there is no cure. A person will never outgrow the disorder. There are many different types of CMT and how they affect one person will differ from how they affect another person. The nerve damage associated with CMT usually gets worse very slowly and sometimes will remain unchanged for long periods of time. For many of the common forms of the disorder, people can manage the disease and life expectancy will not be affected. However, some people will have significant disability and there are very rare forms of CMT that can cause severe symptoms.

Some forms of Charcot-Marie-Tooth (CMT) disease have reduced penetrance. Penetrance is the proportion of people with a disease-causing change (mutation) in a gene who eventually develop symptoms. Complete penetrance means that 100% of the people who have a gene change will develop symptoms. Reduced (or incomplete) penetrance means that some people who have a disease-causing change will not develop symptoms of the disorder. Specific forms of CMT have reduced penetrance.

A genetic counselor can talk to you and your family about reduced penetrance and the specific genetic changes that affect your family. Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Charcot-Marie-Tooth (CMT) disease is a group of disorders. The severity of these disorders can be very different. This is true for people with the same disorder and members of the same family. Some people will only have mild symptoms and remain active throughout their lives. Other people will have more severe symptoms that can impact their daily lives and their ability to work.

Some people have had to change jobs or move from full-time employment to part-time employment. Talk about your diagnosis and symptoms with your doctor and entire medical team to see what steps you can take to remain as active as possible. If you cannot work because of Charcot-Marie-Tooth disease you may qualify for disability benefits. The Charcot-Marie-Tooth Disease Association and the Hereditary Neuropathy Foundation have information about Social Security benefits.

If you or a family member are diagnosed with Charcot-Marie-Tooth (CMT) disease, and genetic testing has confirmed your diagnosis, it is helpful to share your results with your family. If the altered gene has been identified then siblings and children are at risk of having CMT and could consider genetic testing. Full siblings and children are your 1st degree relatives and share 50% of your DNA. The risk that siblings or children would have CMT as well would depend on how the disorder is inherited in your family, autosomal dominant or recessive inheritance or X-linked inheritance.

Anyone considering genetic testing should seek advice from a medical geneticist or genetic counselor beforehand. A medical geneticist can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website . Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Support groups are organizations that provide support, information, advice, referrals to physicians and medical centers, and up-to-date information on research and treatments. Support groups for Charcot-Marie-Tooth (CMT) disease include the Charcot-Marie-Tooth Disease Association and the Hereditary Neuropathy Foundation.

There are also online communities for rare disorders such as RareConnect, RareShare, or Inspire, which allow individuals and parents to share experiences and advice about dealing with rare disorders.

For some families, the medical cost of Charcot-Marie-Tooth (CMT) disease can be significant. Some families lack the resources necessary to provide for a chronically ill or disabled child. There are several organizations that provide financial assistance.

The Social Security Administration provides disability benefits for people who qualify. Charcot-Marie-Tooth disease is not listed in the publication called the Disability Evaluation Under Social Security, also called the "Blue Book." However, CMT is a form of peripheral neuropathy and peripheral neuropathy does qualify.

The National Organization for Rare Disorders has links to organizations that can provide financial assistance.

The National Human Genome Research Institute has extensive information on finding financial aid for medical treatment and services.

It is extremely important that children and adults with Charcot-Marie-Tooth (CMT) disease receive psychological support. This means that they should receive help for any psychological or social problems they may have. Some children and adults, especially those with mild symptoms, may have no issues with adapting to and living with chronic illness. However, others may struggle with these issues. Some children feel different from their friends, which can lead to feelings of isolation, anxiousness, depression and frustration. They may struggle with low self-esteem and making and keeping friendships.

These are normal feelings for individuals and families dealing with a chronic illness. Talk to your doctor and medical team about how to deal with such issues. It is beneficial to talk to other people and families that are dealing with the challenges of CMT. Doctors, genetic counselors, and social workers can provide emotional support for such issues. For depression or other mood issues, counseling by a psychologist or being treated by a psychiatrist may be helpful as well.

There are several support groups for CMT that provide advice and support and help bring people with these disorders together. These groups include: the Charcot-Marie-Tooth Disease Association and the Hereditary Neuropathy Foundation.

Taking care of someone with a long-term or chronic condition can be tiring and challenging and this is no different for parents or other caregivers of people with Charcot-Marie-Tooth disease. If you are a caregiver in need of support, try to take time for yourself, set aside time for personal counseling, or look for other resources at the Caregiver Action Network. This organization works to improve the quality of life for people who care for loved ones with chronic conditions, disabilities, disease, or the frailties of old age. Support groups can also help provide support and advice for caregivers. Support groups for Charcot-Marie-Tooth disease include Charcot-Marie-Tooth Disease Association and the Hereditary Neuropathy Foundation.

People with Charcot-Marie-Tooth (CMT) disease are counseled to avoid certain medications that can make their disease worse. These medications are called ‘neurotoxins.’ They are medications that, in high enough doses, can damage the nervous system. Because CMT is a peripheral neuropathy (a disorder that affect the peripheral nerves), patients are more susceptible to these medications. Taking them can make their disease worse. The Charcot-Marie-Tooth Disease Association has information on which drugs should be avoided or taken with extreme care. The list is broken down by how significant the risk is.

Charcot-Marie-Tooth disease is a general term for a group of inherited disorders that affect the peripheral nerves. These are the nerves that are outside the central nervous system, which encompasses the brain and spinal cord. 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.

Because CMT includes so many disorders, doctors cannot make broad statements about how the disorder may affect someone. The damage to the peripheral nerves usually gets worse slowly. For people with the most common forms of CMT, life expectancy is usually not reduced. However, there are rare forms of CMT that cause more severe problems.

Talk to your or your child’s doctor about specific form of CMT that affects your family. The Charcot-Marie-Tooth Disease Association has information these disorders and a listing of CMT Centers of Excellence, which are medical centers that specialize in treating these disorders.

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.

Support groups offer in-depth information about CMT. The Charcot-Marie-Tooth Association and the Hereditary Neuropathy Association offer information and support for these disorders.

Charcot-Marie-Tooth disease is a large group of disorders. Each disorder is caused by a change in a gene; a mutation or another genetic change. Not all changes in a gene necessarily cause disease. If a change is known to cause CMT, it is known as a pathogenic or disease-causing variant. Most people with a pathogenic variant in one of these genes eventually develop symptoms of the disorder, but sometimes symptoms may be very mild. Sometimes gene changes are found and scientists are unsure what it means, either because it has not been found before or has only been found in a few people. This is known as a variant of unknown significance. If you have a variant of unknown significance in one of these genes, talk to your doctor about further testing that may help find out whether the gene change is pathogenic or not. A genetic counselor may also be able to help you review your test results. Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Rare diseases that affect multiple organ systems like Charcot-Marie-Tooth (CMT) disease can benefit from a multidisciplinary approach. This approach involves healthcare professionals with specialized skills and expertise. They work together to make treatment recommendations and to provide quality care of individuals and families. Depending upon the specific symptoms in an individual multidisciplinary team may require a specialist who can assess and treat disorders of the brain and central nervous system in child (pediatric neurologist) or adults (neurologist); a specialist who can assess and treat disorders of the skeleton and bone (orthopedist); orthopedic surgeons; a genetic counselor who can help people understand the disease and the implications for the person and other family members; social workers; and occupational and physical therapists.

Talk to your doctor about the best specialists in your area to follow an individual with CMT. The Charcot-Marie-Tooth Disease Association has information on CMT Centers of Excellence, which are medical centers that specialize in treating these disorders.

Charcot-Marie-Tooth disease or CMT is a group of genetic disorders. They are caused by a change (mutation or another alteration) in a gene. People have about 20,000-25,000 genes in their bodies. Our genes contain our body’s genetic information, called DNA; genes are segments of DNA found on chromosomes. Genes are inherited from our parents and passed on to our children. Genes are like our body’s instruction manual – they control the growth, development and normal function of the body. Genes produce specific proteins that the body needs to grow and work properly. When there is an unexpected change in a gene, the protein that the gene produces may be absent or not work properly or be overproduced.

There are more than 40 different genes or loci associated with CMT. Loci are areas on a chromosome where doctors believe that an altered gene that cause CMT is located, but the specific gene has not been identified yet.

A medical professional nearby can discuss information about gene changes in CMT. A medical geneticist can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website . Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Some forms of Charcot-Marie-Tooth (CMT) can cause significant problems in childhood. Children may need devices such as braces or canes to help them walk. Some children may require a wheelchair like CMT2A. When infants and children have a chronic disorder like CMT, it demands a lot of time and focus from parents. As with similar disorders, it is easy for healthy siblings to feel as if they have been pushed aside. Although studies have shown that siblings of children with chronic illness tend to develop strong levels of compassion and empathy, these studies have also shown that siblings can develop feelings of jealousy, anger, and high levels of anxiety. Parents can work with siblings by having clearly defined roles and responsibilities within the family structure. Siblings can help with the care of their sick sibling. Parents are encouraged to make time for activities, especially for healthy siblings, and to talk with and encourage healthy siblings to address their concerns and feelings. Some children may benefit from support outside of the immediate family including therapists or doctors. The Sibling Support Project is a nonprofit organization that serves the concerns and needs of siblings of people with special health, developmental, and mental health needs.

Charcot-Marie-Tooth disease, or CMT, is a group of disorders. Some forms are caused by an altered gene on the X chromosome. These disorders are called CMTX and several forms have been identified, called CMTX1 through CMTX5. CMTX1 is the second most common form of CMT in European and American people. Because this is an X-linked disorder, it affects boys and men more often and more severely. Girls or women are usually either unaffected or have mild symptoms.

Symptoms usually begin in the first or second decade of life. Sometimes, infants have symptoms or people reached adulthood without symptoms developing. The severity these disorders can range from mild disease that goes unnoticed by the affected person or doctors to severe disease that can be disabling. Usually, is a more severe disorder than CMT1A, the most common form of CMT.

Weakness of the feet and ankles is the most common symptom of CMTX1. Children and adults may have muscle weakness, muscle wasting, muscle cramps, and a mild loss of sensation in the feet and legs, which means they may be less sensitive to touch, heat or pain. People with CMTX1 may sprain their ankles a lot, trip and fall a lot and appear clumsy, and they may have a high arch to the bottom of their feet, or toes that bend upward at the middle joint (hammertoes). Some children will not be able to keep up with their peers. Children or adults may walk with a high-steps because their when they lift their foot to take a step, the foot drops, making it harder to walk. Sometimes, the hands 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.

Some people have tremors or hearing loss, and central nervous system problems like trouble speaking, trouble swallowing, poor coordination and weakness of the arms and legs can also develop. The problems of CMTX1 get slowly worse. However, people may go many years during which the severity of symptoms remains generally the same. Lifespan is usually not shortened.

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. The central nervous system or CNS is made up of 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, particularly in the legs and feet. 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.

Because CMT is a group of disorders, the signs and symptoms can be very different in one person when compared to another person. This is true even for members of the same family. For some people, the disease is mild throughout their life and does not cause significant problems. They remain active throughout their lives and some may never know they have CMT. In other people, there may be issues in childhood and some children may need help to walk. Rare forms like CMT type 3 or CMT type 4 can have severe, even life-threatening complications. Most people have CMT type 1, type 2 or an X-linked form (CTMX).

The most common symptoms are slow degeneration of muscles in the feet and legs causing muscle weakness, muscle wasting, muscle cramps, and a mild loss of sensation in the feet and legs, which means they may be less sensitive to touch, heat or pain. The specific symptoms can differ among people with this disorder; this is even true for people in the same family. As the disease progresses, people may be sprain their ankles a lot, trip and fall a lot and appear clumsy, and they may have a high arch to the bottom of their feet, or toes that bend upward at the middle joint (hammertoes). Some children will not be able to keep up with their peers. Children or adults may walk with a high-steps because their foot drops when they try and lift it, making it harder to walk.

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. Pain and fatigue can be chronic or persistent.

Symptoms usually begin in the teens or early adulthood, but can also start years later or earlier. Sometimes, infants have symptoms. Sometimes children are moderately affected and sometimes they are severely affected.

Other symptoms that can happen include abnormal curving of the spine called scoliosis or kyphosis or malformation (dysplasia) of the hips. Some people have problems when they try and sleep like sleep apnea or restless legs syndrome. There are very rare forms of CMT that can cause additional symptoms affecting other organ systems of the body.

CMT rarely affects intelligence or the function of the brain.

Charcot-Marie-Tooth disease, or CMT, is a group of disorders. CMT2 is a specific subtype and can be further subdivided. These forms are called CMT2A through CMT2P; sometimes the exact number of subtypes differ depending on the medical reference cited. Symptoms usually begin in the first or second decade of life. Sometimes, infants have symptoms or people can reach adulthood without symptoms developing. The severity these disorders can range from mild disease that goes unnoticed by the affected person or doctors to severe disease that can be disabling.

Weakness of the feet and ankles is the most common symptom of CMT2. Children and adults may have muscle weakness, muscle wasting, and muscle cramps. Some people may have a mild loss of sensation in the feet and legs, which means they may be less sensitive to touch, heat or pain. Children and adults may sprain their ankles a lot, trip and fall a lot and appear clumsy, and they may have a high arch to the bottom of their feet, or toes that bend upward at the middle joint (hammertoes). Some children will not be able to keep up with their peers. Children or adults may walk with a high-steps because their when they lieft their foot to take a steop, their foot drops, making it harder to walk. Sometimes, the hands 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.

The problems of CMT2 get slowly worse. However, people may go many years during which the severity of symptoms remains generally the same. There are differences among these subtypes. Some of these differences are:

CMT2B is a specific subtype that causes significant sensory involvement.

Some people with CMT2C may have paralysis of the vocal cords.

CMT2I tends to develop in people over the age of 45.

CMT2J can cause deafness or abnormalities of the pupils of the eyes.

Charcot-Marie-Tooth disease, or CMT, is a group of disorders. CMT1 is the most common form and is further divided into specific subtypes, called CMT1A through CMT1F. Symptoms usually begin in the first or second decade of life. Sometimes, infants have symptoms or people can reach adulthood without symptoms developing. The severity these disorders can range from mild disease that goes unnoticed by the affected person or doctors to severe disease that can be disabling.

Weakness of the feet and ankles is the most common symptom of CMT1. Children and adults may have muscle weakness, muscle wasting, muscle cramps, and a mild loss of sensation in the feet and legs, which means they may be less sensitive to touch, heat or pain. People with CMT1 may sprain their ankles a lot, trip and fall a lot and appear clumsy, and they may have a high arch to the bottom of their feet, or toes that bend upward at the middle joint (hammertoes). Some children will not be able to keep up with their peers. Children or adults may walk with a high-steps because when they lift their foot to take a step, their foot drops, making it harder to walk. Sometimes, the hands 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.

The problems of CMT1 get slowly worse. However, people may go many years during which the severity of symptoms remains generally the same.

After an initial diagnosis of Charcot-Marie-Tooth (CMT) disease, your doctor will take a comprehensive medical history. People with CMT should receive information about their disorder and work with doctors to develop and an overall treatment plan. Depending on the subtype and whether the altered gene that causes the disorder is known, doctors may recommend testing family members to see whether they also have the disorder.

The best way to obtain the most accurate, current, clear, and comprehensive information is to be seen at a CMT Center of Excellence. These are genetic centers that specialize in the treatment of patients with CMT. At most centers, you will see a medical geneticist, genetic counselor, and nurse who work as a team to answer your questions, discuss testing, identify your at-risk family members, and develop a comprehensive evaluation and treatment plan for you. A Center will work with your current doctors to organize the treatment, tests, and specialists you need. The Charcot-Marie-Tooth Disease Association has information on CMT Centers of Excellence throughout the United States.

Charcot-Marie-Tooth disease or CMT is not one of the disorders that is screened for at birth. Most people develop symptoms when they are teenagers or young adults . However, some people develop symptoms much later and some can develop symptoms earlier. If a child appears to have health problems that could be caused by CMT, the easiest way to begin testing for the disorder is to discuss it with the pediatrician or primary doctor. Referral to a pediatric neurologist may be necessary. Testing information in your area can also be obtained through a genetic counselor, to find a genetic counselor visit the National Society of Genetic Counselors Find a Genetic Counselor website. Information about newborn screening programs can be found at Save Babies Through Screening Foundation or Baby’s First Test.

A doctor may suspect a diagnosis of Charcot-Marie-Tooth (CMT) disease because of certain symptoms. These signs can include muscle weakness particularly of the legs, difficulty lifting the feet when walking, or a loss of reflexes in the legs. Physical signs like toes that are curled so that the middle knuckle in rounded up (hammer toes), or a high arch to the bottom of the foot may also be seen.

Two tests that may be ordered are the nerve conduction velocity test and an electromyogram. These tests tell the doctor how well the motor or sensory nerves function. Motor nerves cause muscles to contract and allow people to perform voluntary functions 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.

A nerve conduction velocity test is when the motor and sensory nerves are electrically stimulated so doctors can determine how well the nerves pass along nerve impulses. Doctors will place an electrode on a motor or sensory nerve and stimulate the nerve with a small electric charge that can cause mild discomfort. How the nerves respond to this electric charge will be recorded and evaluated to see how well the nerves pass along nerve impulses.

An electromyogram records the electrical activity of muscles when they are at rest and when they are being used. This test uses a needle electrode, which is a very thin wire through which doctors can send an electrical charge. The needle electrode is inserted through the skin into the muscle where it can record the electrical activity of the muscle.

Some forms of CMT can be diagnosed through genetic testing. These tests involve studying the genes known to cause specific forms of CMT, like the PMP22 and MPZ genes, for mutations or other changes. Doctors do not know the underlying genetic cause of all forms of CMT, so these tests cannot confirm a diagnosis for everyone with CMT.

Clinical research can be found at the following:

https://clinicaltrials.gov/ These are studies receiving US government funding. Some studies are supported by private industries.

In Europe, the EU Clinical Trial Register performs a similar service.
To learn about clinical trials sponsored by private sources, you can contact www.centerwatch.com

The Inherited Neuropathies Consortium (INC) is a group of academic medical centers, patient support organizations, and clinical research resources dedicated to conducting clinical research in different forms of CMT and improving the care of people with these disorders.

For the most up-to-date list, contact clinical trials.gov and search for Charcot-Marie-Tooth disease. The U.S. Food and Drug Administration (FDA) has information for patients about clinical trials.

A patient registry is a database set up by researchers that contains information about patients with a particular disorder or group of disorders. This information helps researchers learn about a disorder, plan or study treatments, how a disorder progresses or affects people and other information. Patient registries require that patients either directly or through their doctor submit personal information. Talk to a genetic counselor about the pros or cons of participating in a patient registry. There is a patient registry for inherited neuropathies including Charcot-Marie-Tooth disease. The Hereditary Neuropathy Foundation has information on this registry.

There is no cure for Charcot-Marie-Tooth (CMT) disease. There are many supportive treatments that help people manage these disorders. Physical therapy, which can strengthen muscles, and occupational therapy, which helps people perform everyday tasks that may be difficult because of their illness. Exercise is also recommended, although a person’s individual tolerance for exercise will be different from another person’s. Daily stretching, early during the course of the disease, has helped to strengthen the ankles.

Some people may benefit from medical devices such as special shoes with extra ankle support, braces or splits that provide support for the ankles, devices like foot pads or inserts that provide support or relief for problems of the feet, leg braces or splints, or forearm crutches. Some problems may require surgery including deformities of the feet or malformation of the hips. Abnormal curving of the spine (scoliosis or kyphosis) is usually mild when it occurs. However, if it is severe, scoliosis or kyphosis may also require surgery to fix.

Over-the-counter pain medications can help people with CMT as well. If pain is severe or debilitating, a doctor can prescribe stronger pain medications. A drug called, modafinil, may be prescribed to treat fatigue.

Because CMT is a large group of disorders, there can potentially be many other symptoms people may have based on their specific subtypes. Talk to your doctor and medical team about your or your child’s specific diagnosis and discuss the best treatment options for your situation.

Charcot-Marie-Tooth (CMT) disease can cause chronic pain. Pain can be mild or severe. Pain can be treated with medications that reduce pain, and many people require relief of pain through medication. For long-term, chronic pain, doctors may recommend that patients seek mental health services. Behavioral and psychological therapy may be beneficial in helping people cope with chronic pain.

The Charcot-Marie-Tooth Disease Association or the Hereditary Neuropathy Foundation can provide advice and support about dealing with chronic pain in CMT. There are several organizations that provide support, advice and guidance for people with chronic pain including the American Chronic Pain Association.

This is very common question about a lot of genetic disorders. In Western countries, the autosomal dominant forms of CMT are the most common. Autosomal dominant inheritance means that a person receives one nonworking copy of the gene in question. With autosomal dominant inheritance, the one nonworking copy of the gene is sufficient to cause symptoms of the disorder. The risk of passing an altered gene through autosomal dominant inheritance is 50% for each pregnancy. This is true regardless if the child is a boy or girl. However, sometimes there is no history of CMT in a family and a person is the first person in the family to have CMT. This is because sometimes an alteration (mutation or other change) to the gene can also happen at random for no known reason. This is called a de novo mutation. Talk to a genetic counselor to learn more about the genetics of CMT.Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Charcot-Marie-Tooth disease can be inherited in autosomal dominant, autosomal recessive, or X-linked manner. People get two copies of most of their genes. One copy comes from their mothers and the other copy comes from their fathers. In autosomal dominant inheritance, only one nonworking copy of a gene needs to be passed on from a parent. Therefore, only one parent needs to be a carrier for the autosomal dominant forms of CMT. The risk of passing an altered gene through autosomal dominant inheritance is 50% for each pregnancy. This is true regardless if the child is a boy or girl. Sometimes an autosomal dominant disorder can occur even if neither parent has an altered gene. This happens when there is a new or ‘de novo’ mutation in a gene. This gene change occurs spontaneously. The likelihood of another child in this family having CMT is very low.

In autosomal recessive inheritance both parents must pass along a nonworking copy of the gene in question. People who have one working and one nonworking copy of such a gene are called carriers. When both parents are carriers, for each individual pregnancy, there is a 25% chance that both parents will pass along a nonworking copy of the gene and the child will have the disorder. There is a 50% chance that one parent will pass on the gene change and the other will not, meaning the child will be a carrier for the disorder. Finally, there is a 25% chance that both parents will pass along a working copy of the gene and the child will not have the disorder and will not be a carrier.

In X-linked inheritance, the altered gene is passed from parent to child on the X chromosome. If a woman is a carrier for X-linked CMT, it means that she carries one altered gene that does not work properly, and one unaltered gene that does work properly. Women who are carriers usually do not have symptoms of these disorders because the unaltered copy of the gene can usually compensate for the altered copy. When a woman who is a carrier has a child, there is a 50% chance for her to pass on the altered copy and a 50% chance for her to pass on the unaltered copy. Her sons who inherit the altered copy will have CMT; her daughters who inherit the altered copy will be carriers like her. Children who inherit the unaltered copy will not have the disorder and cannot pass the genetic change onto their children.

Men only one X chromosome. So, if a man has CMT then his X chromosome contains an altered copy of the gene that causes the disorder. He will pass this X chromosome on to all of his daughters, who will be carriers. Men pass their Y chromosome onto their sons, so men with X-linked CMT cannot pass the disorder onto their sons.

A genetic counselor can help explain autosomal dominant, autosomal recessive and X-linked inheritance and how CMT is passed from generation to generation in families. Genetic counselors can also talk to people who want to get tested to see whether they are a carrier for CMT. Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Charcot-Marie-Tooth disease or CMT can be inherited in an autosomal dominant, an autosomal recessive, or X-linked manner. These are a few of the ways a disorder or trait can be passed down through a family.

With autosomal dominant or recessive inheritance, there is a change (mutation or other alteration) in a gene or genes. Everyone has two copies of most genes; one received from their father and one from their mother. Autosomal dominant inheritance means that a person receives one nonworking copy of the gene in question. With autosomal dominant inheritance, the one nonworking copy of the gene is sufficient to cause symptoms of the disorder. The risk of passing an altered gene through autosomal dominant inheritance is 50% for each pregnancy. This is true regardless if the child is a boy or girl. Sometimes there is no family history of CMT and the change in the gene that causes the disorder occurs randomly for unknown reasons and is not inherited. This is called a de novo mutation and the likelihood of another child having CMT in the family is very low.

Some forms have autosomal recessive inheritance. Autosomal recessive inheritance is when a person receives a nonworking copy of the gene in question from both parents. This means that the parents have one working copy of the gene and one nonworking copy; they are carriers for CMT. Carriers do not develop symptoms of the disorder. If two people are carriers for autosomal recessive CMT, there is a 25% chance with each pregnancy that the child will have CMT and a 50% chance the child will also be a carrier and a 25% chance the child will neither have the disorder nor be carrier.

Some forms of CMT are caused by changes in a gene located on the X chromosome. In most instances this change is inherited, or passed down in families. Women have two X chromosomes (XX) and men have one X and one Y chromosome (XY). Women are usually unaffected carriers of CMT and are rarely affected because they have a backup working copy of the altered gene on one of their X chromosomes. Men who inherit a non-working copy of a gene on their X chromosome are affected with CMT because they only have one copy of the X chromosome and do not have a working copy of the gene.

If you have a family member with CMT and you would like to know if you are a carrier or learn more about how CMT is passed on in families, talk to your doctor or meet with a genetic counselor to discuss testing options and modes of inheritance. Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Charcot-Marie-Tooth disease or CMT is a group of genetic disorders. They are caused by a change (mutation or another alteration) in a gene. Our genes contain our body’s genetic information, called DNA; genes are segments of DNA found on chromosomes. Genes are inherited from our parents and passed on to our children. Genes are like our body’s instruction manual – they control the growth, development and normal function of the body. Genes produce specific proteins that the body needs to grow and work properly. When there is an unexpected change in a gene, the protein that the gene produces may be absent or not work properly or be overproduced.

More than 40 different genes or loci are associated with CMT. Loci are areas on a chromosome where doctors believe that an altered gene that cause CMT is located, but the specific gene is not known. These genes produce proteins that are essential for the proper development and function of the peripheral nerves, particularly in the feet, legs, hands and arms. Most forms affect the axons or the cells that produce myelin called Schwann cells. Axons are threadlike parts of nerve cells that transmit nerve impulses from one cell to another. Myelin is a covering of nerve fibers that protects and insulates the nerves and helps to greatly speed up the transmission of nerve impulses. When axons or myelin are damaged or do not function properly, nerve impulses are slowed own or not transmitted to the brain, causing the symptoms of these disorders. When myelin is damaged and cannot function properly, it is called dysmyelination. When axons are damaged and cannot function properly, it is called axonal CMT or non-demyelinating. Some forms of CMT affect both the axons and the myelin.

If a doctor thinks a person has a muscle problem like Charcot-Marie-Tooth disease, it is likely they will conduct a physical exam, ask a series of questions about a patient’s and the family’s medical history, and order several tests. A doctor will check a person for common signs of CMT including muscle weakness particularly in the legs, difficulty lifting the feet when walking, or a loss of reflexes in the legs. Physical signs like toes that are curled so the middle knuckle in rounded up (hammer toes), or a high arch to the bottom of the foot may also be seen.

Two tests that may be ordered are the nerve conduction velocity test and an electromyogram. A nerve conduction velocity test is when the motor and sensory nerves are electrically stimulated so doctors can determine how well the nerves pass along nerve impulses. An electromyogram records the electrical activity of muscles when they are at rest and when they are being used.

Some forms of the disorder can be diagnosed through genetic testing. These tests involve studying the genes known to cause forms of CMT, like the PMP22 and MPZ genes, for mutations or other changes. Doctors do not know the underlying genetic cause of all forms of CMT.

To find a genetic professional near you who can discuss genetic testing, visit the following sites: A medical geneticist can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website . Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

To learn about ongoing clinical research into Charcot-Marie-Tooth (CMT) disease ask a physician who specializes in the disorder. Genetic counselors and medical geneticists are also excellence sources of information about ongoing clinical trials and can offer advice about the pros and cons about participating in such a trial. A medical geneticist can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website . Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Ongoing studies for Charcot-Marie-Tooth disease can also be found on clinicaltrials.gov, a service of the U.S. National Institutes of Health. In Europe, the EU Clinical Trial Register performs a similar service.

Support groups also have information about ongoing clinical trials as well as information and advice about participating in clinical trials. Support groups for Charcot-Marie-Tooth disease include the Charcot-Marie-Tooth Disease Association and the Hereditary Neuropathy Foundation.

The Inherited Neuropathies Consortium (INC) is a group of academic medical centers, patient support organizations, and clinical research resources dedicated to conducting clinical research in different forms of CMT and improving the care of people with these disorders.

The best way to obtain the most accurate, current, clear, and comprehensive information is to be seen at a Charcot-Marie-Tooth disease or CMT Center of Excellence. These are genetic centers that specialize in the treatment of patients with Charcot-Marie-Tooth disease. At most centers, you will see a medical geneticist, genetic counselor, and nurse who work as a team to answer your questions, discuss testing, identify your at-risk family members, and develop a comprehensive evaluation and treatment plan for you. A Center will work with your current doctors to organize the treatment, tests, and specialists you need. The Charcot-Marie-Tooth Disease Association has information on Centers of Excellence.

Some people with Charcot-Marie-Tooth (CMT) disease find it challenging when it’s time to move (transition) from pediatric to adult health care services. One big change is leaving a doctor with whom you have a long-standing relationship, a doctor who is familiar with both your condition and you. It can feel like ‘starting over’ as you’ll begin to work with new doctors and a new medical team. Another challenge in moving to adult care is that young adults must take greater responsibility for their health. They must manage their disorder and manage their medications. They must bear greater responsibility for decisions concerning their health. Adolescents should be encouraged to make decisions about their care as early as possible to make this transition easier. Some hospitals have programs to help children with chronic disease transition to adult care services.

Children with Charcot-Marie-Tooth (CMT) disease can attend school. Intelligence is usually not affected, and children can do very well in school. Some children with CMT may need special accommodations. Their disease may require them to wear braces or custom-made shoes. Because they may need special accommodations in school, they may eligible for an individual education plan (IEP) or a 504 plan. An IEP is a document that helps to guide the education of a child with a disability or special needs. The plan is individualized for each student. A 504 plan ensures that students with disabilities can fully participate in school and have access to the same educational opportunities as all children. Parents are encouraged to provide a school with a packet of information on CMT and to work with school officials including teachers, nurses, psychologists, the principal, and other professionals.

The U.S. Department of Education has information on individual education plans and on 504 plans. The Charcot-Marie-Tooth Association has resources and information for children and teen-agers with CMT, including ways to talk to other kids with CMT. They also have information on 504 and IEPs plans for CMT, a guide for schools, a guide for school nurses and more.

Global Genes, a rare disease advocacy organization, has a RARE Toolkit that advises parents on advocating for their children at their school.

Charcot-Marie-Tooth disease is one of the most common genetic cause of nerve disease (neuropathy) in the world. The prevalence is estimated to be about 1 in 2,500-3,300 people in the general population of Western countries. However, specific geographic populations have different prevalence rates ranging from 1 in 1,200 to 1 in 9,200. Prevalence is the total number of people with a disorder in a specific population at a given time. Collectively, these disorders affect more than 250,00 people in the United States, and may affect as many as 2.8 million people worldwide. Most people in Western countries have CMT1, which makes up about 80% of people with these disorders. The main subdivision, CMT1A makes up about 70%-80% of people with CMT1.

The most common forms of Charcot-Marie-Tooth disease in Europe and American populations are inherited in autosomal dominant manner. CMT1X is also a common form and is inherited as an X-linked trait. These disorders do not skip a generation. However, some people may be so mildly affected that no one realizes that they have the disorder and it can appear as if it skips a generation.

Autosomal dominant inheritance means that a person receives one nonworking copy of the gene in question from one of their parents (or it occurs randomly). With autosomal dominant inheritance, the one nonworking copy of the gene is sufficient to cause symptoms of the disorder. In most instances, CMT1X is inherited, or passed down in families. Women have two X chromosomes (XX) and men have one X and one Y chromosome (XY). Women are usually unaffected carriers of CMT and are rarely affected because they have a backup working copy of the altered gene on one of their X chromosomes. Men who inherit a non-working copy of a gene on their X chromosome are affected with CMT because they only have one copy of the X chromosome and do not have a working copy of the gene.

Talk to a genetic counselor to learn how gene changes are passed down through a family and how your specific form of CMT can affect other family members. Genetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Charcot-Marie-Tooth (CMT) disease is a group of disorders. Most of these disorders do not affect intelligence and most people with CMT will have no intellectual problems. However, there are very rare forms that can affect intelligence like CMTX4 (also called Cowchock syndrome). This is an extremely rare form. In fact, if a person has intellectual disability, it is likely that they have a different disorder and not CMT. The Arc is an organization that provides support and information for children and adults with intellectual disability.

Parents who have a family history of Charcot-Marie-Tooth (CMT) disease (or if one parent has an altered gene known to cause a form of CMT) may choose to have their child tested for the disorder before the child is born. This is known as prenatal diagnosis. If the gene change(s) that causes CMT are known in a family, then molecular genetic testing (which can detect these changes) can be used for prenatal diagnosis. In Europe and North America, the autosomal dominant forms of CMT are the most common. Prenatal testing for genetic conditions that commonly present in adulthood is uncommon and need careful consideration and genetic counseling is recommended.

Preimplantation genetic diagnosis (PGD) in which embryos can be genetically tested is also available. During this process, embryos are created through in vitro fertilization (IVF) by taking eggs from the mother and sperm from the father. The two are then combined in the laboratory. A few cells are removed from the embryo and are then tested to determine whether or not that specific embryo inherited the altered gene. Then, the family can choose to only have the embryos without the altered gene transferred to create the pregnancy.

Genetic counselors are great resources to help families discuss the options for family planning. TGenetic counselors in the United States can be found on the National Society of Genetic Counselors website. Genetic counselors in Canada can be found at the Canadian Association of Genetic Counselors website.

Most doctors and medical personnel refer to these disorders as Charcot-Marie-Tooth disease. Charcot, Marie and Tooth are the surnames of three of the doctors who first described this disorder in the medical literature. Drs. Jean-Martin Charcot, Pierre Marie, and Howard Henry Tooth first wrote about this disorder in 1886.

Charcot-Marie-Tooth disease is often abbreviated as CMT and is also called Charcot-Marie-Tooth syndrome, hereditary motor and sensory neuropathy or HMSN, Charcot-Marie-Tooth neuropathy, and Charcot-Marie-Tooth hereditary neuropathy.

As doctors learn more about CMT, they have determined that disorders that were once thought of as distinct disorders are actually specific forms of CMT. Dejerine-Sottas syndrome and congenital hypomyelinating neuropathy were once considered distinct disorders. Doctors now believe that they are the same disorder and they are now classified as Charcot-Marie-Tooth disease type 3 or CMT3. Roussy-Levy syndrome is now considered a subtype of CMT type 1. Peroneal muscular atrophy is now classified as CMT1B.

Support groups are organizations that provide support, information, advice, referrals to physicians and medical centers, and up-to-date information on research and treatments. Support groups for Charcot-Marie-Tooth (CMT) disease include the Charcot-Marie-Tooth Disease Association and the Hereditary Neuropathy Foundation. The Center for Peripheral Neuropathy also provides information on CMT.

Charcot-Marie-Tooth (CMT) disease is a group of disorders. According to the Charcot-Marie-Tooth Disease Association, there are about 90 different kinds of CMT. The classification and different names used to describe these disorders can be very confusing. The two major subdivisions are CMT1 and CMT2.

Most of the people in Western countries diagnosed with CMT have CMT1. CMT1 has several subtypes of its own (CMT1A-CMT1F). The symptoms occur because of damage to the myelin sheath. Myelin is a fatty covering that protects and insulates the axons of some nerve cells. Axons are threadlike parts of nerve cells that transmit nerve impulses from one cell to another. Myelin also greatly speeds up the transmission of nerve impulses. CMT1A is the most common type of Charcot-Marie-Tooth disease. CMT2, which also has more than 10 subtypes, is less common than CMT1. These disorders occur because of damage to axons themselves.

Most people with CMT1 or CMT2 have an autosomal dominant form. Autosomal dominant is one way a gene or trait is passed on in a family. Everyone has two copies of autosomal genes; one received from your mother and one from your father. Autosomal dominant inheritance means that a person receives one nonworking copy of the gene in question. This is sufficient to cause the disorder. Sometimes, an autosomal dominant change to a gene occurs randomly. This is called a de novo mutation, and means that there is no family history of the disorder.

There are also intermediate forms of CMT. In these forms, there is damage to both the axons and the myelin.

Some people have autosomal recessive inheritance, which means that they must receive a nonworking copy of a gene from both parents. Most forms of autosomal recessive CMT are classified as CMT4. These types are usually more severe and develop earlier in life than the autosomal dominant forms. There are far less common than CMT1 or CMT2.

Some people have X-linked CMT, in which the altered gene that causes the disorder is found on the X chromosome. These disorders are classified as CMTX. There are six subtypes, CTMX1-CTMX6. CMTX1 is the second most common form of Charcot-Marie-Tooth disease and makes up more than 90% of X-linked CMT. Usually, X-linked disorders affect boys and men more severely than girls or women. This is because girls have two X chromosomes and boys only have one. In girls or women, the corresponding gene one X chromosome can sometimes compensate for the altered gene on the other X chromosome.

CMT3 is a very rare and very severe form of the disorder that is also known as Dejerine-Sottas syndrome or congenital hypomyelinating neuropathy.

The Charcot-Marie-Tooth Disease Association and the Hereditary Neuropathy Foundation have information about the various types of CMT.

Doctors recommend that people with Charcot-Marie-Tooth (CMT) disease exercise and stay as active as their disease allows them. Some people will remain active their entire lives and have a normal lifespan. Exercise can help to build muscle and bone strength. Doctors also recommend that people with CMT eat healthy and maintain a healthy weight. Obesity can make it harder to walk and many people with CMT already have issues with walking. Doctors also encourage people to have a daily stretching program. There are also many other benefits to exercise and eating right that apply to everyone, not just people with CMT. Better sleep quality, better cardiovascular health, weight loss and improved mental alertness. Children and adults with CMT will benefit from a program of appropriate physical activity and exercise. This program will be created by a person’s doctor and other healthcare professionals like physical therapists. The specifics of such a program will depend on a person’s age, severity of their condition, ability to function, and the person’s personal desires or objectives.

The Charcot-Marie-Tooth Disease Association has information on the benefits of exercise for people with CMT.