National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Charcot-Marie-Tooth disease type 2F


Other Names:
CMT 2F; Charcot-Marie-Tooth disease, axonal, Type 2F; Charcot-Marie-Tooth disease, neuronal, Type 2F; CMT 2F; Charcot-Marie-Tooth disease, axonal, Type 2F; Charcot-Marie-Tooth disease, neuronal, Type 2F; Charcot Marie Tooth disease type 2F; Charcot-Marie-Tooth neuropathy, type 2F See More
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Charcot-Marie-Tooth disease type 2F (CMT2F) is a genetic disorder of the peripheral nerves. The subtypes of CMT type 2 (including type 2F) have similar features and are distinguished only by their disease-causing genes. Signs and symptoms usually begin between the ages of 5 and 25 and typically include slowly progressive weakness and atrophy of distal muscles in the feet and/or hands, usually associated with decreased tendon reflexes and mild or no sensory loss. Nerve conduction velocities are usually normal or near-normal. CMT2F is caused by mutations in the HSPB1 gene and is inherited in an autosomal dominant manner. Management may include occupational and physical therapy; special shoes; surgery as needed; mobility aids; and other supportive treatments.[1]
Last updated: 7/31/2012
The subtypes of Charcot-Marie-Tooth type 2, including type 2F, have similar signs and symptoms. Affected individuals usually become symptomatic between the ages of 5 and 25, though onset can range from infancy to after the third decade of life. The most common first symptom is weakness of the feet and ankles, followed by slowly progressive weakness and atrophy of distal muscles in the feet and/or hands. Individuals often have decreased tendon reflexes and mild or no sensory loss.

Adults with CMT2 often have bilateral foot drop, symmetric atrophy of muscles below the knee (stork leg appearance) and absent tendon reflexes in the legs. Mild sensory deficits of position, vibration, pain or temperature may occur in the feet, or sensation may be intact. Pain (especially in the feet) is reported by about 20%-40% of affected individuals. Other features that may be associated with CMT2 in a few individuals include hearing impairment; vocal cord or phrenic nerve involvement (which may result in difficulty with speech or breathing); restless legs; and sleep apnea.

CMT2 is progressive over many years, but affected individuals often experience long periods without obvious progression. In some individuals, the condition may be so mild that it goes unrecognized. Affected individuals have a normal life span.[1]
Last updated: 8/1/2012

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
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HPO ID
80%-99% of people have these symptoms
Distal lower limb amyotrophy 0008944
EMG: chronic denervation signs 0003444
Impaired pain sensation
Decreased pain sensation
0007328
Impaired temperature sensation
Abnormality of temperature sensation
Loss of temperature sensation
[ more ] 		0010829
Limb fasciculations 0007289
Lower limb muscle weakness
Lower extremity weakness
Lower limb weakness
Muscle weakness in lower limbs
[ more ] 		0007340
Peripheral axonal neuropathy 0003477
Reduced tendon reflexes 0001315
Steppage gait
High stepping
0003376
Talipes equinovarus
Club feet
Club foot
Clubfeet
Clubfoot
[ more ] 		0001762
Upper limb amyotrophy 0009129
Percent of people who have these symptoms is not available through HPO
Areflexia
Absent tendon reflexes
0001284
Autosomal dominant inheritance 0000006
Chronic axonal neuropathy 0007267
Decreased motor nerve conduction velocity 0003431
Distal amyotrophy
Distal muscle wasting
0003693
Distal muscle weakness
Weakness of outermost muscles
0002460
Distal sensory impairment
Decreased sensation in extremities
0002936
Fasciculations
Muscle twitch
0002380
Foot dorsiflexor weakness
Foot drop
0009027
Hyporeflexia
Decreased reflex response
Decreased reflexes
[ more ] 		0001265
Muscle spasm 0003394
Pes cavus
High-arched foot
0001761
Split hand
Claw hand
Claw hand deformities
Claw hands
Claw-hand deformities
Split-hand
[ more ] 		0001171
Ulnar claw 0001178
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Last updated: 7/1/2020
Charcot-Marie-Tooth disease type 2F (CMT2F) is caused by mutations in the HSPB1 gene. This gene provides instructions for making a protein (heat shock protein beta-1) which helps protect cells under adverse conditions. Heat shock proteins appear to be involved in activities such as cell movement, stabilizing the cell's framework, folding and stabilizing new proteins, repairing damaged proteins, and muscle contraction. Heat shock protein beta-1 is particularly abundant in nerve and muscle cells. In nerve cells, it helps to organize a network of threads that maintain the diameter of axons (neurofilaments), which are needed to transmit nerve impulses efficiently.

It is unclear exactly how HSPB1 mutations lead to the axon abnormalities characteristic of CMT2F. Researchers suggest that mutations lead to an altered protein which clusters together and interferes with nerve cell function. Another possibility is that the altered protein disrupts the assembly of neurofilaments, which in turn may impair the transmission of nerve impulses.
Last updated: 8/1/2012
Charcot-Marie-Tooth disease type 2F is inherited in an autosomal dominant manner. This means that only one mutated copy of the gene in each cell is sufficient to cause the condition. Most affected individuals inherit the mutated gene from an affected parent, but in some cases the mutation occurs for the first time in the affected individual (de novo mutation).[1] When an individual with an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit the mutated gene and have the condition.
Last updated: 8/1/2012
Yes. GeneTests lists the names of laboratories that are performing clincial genetic testing for Charcot-Marie-Tooth disease type 2F. To view the contact information for these laboratories, click here. Please note that most of the laboratories listed through GeneTests do not accept direct contact from patients and their families; therefore, if you are interested in learning more, you will need to work with a health care provider or a genetics professional.
Last updated: 8/1/2012

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Treatment for Charcot-Marie-Tooth disease type 2 mainly focuses on the specific symptoms present. Affected individuals are often managed by a team of various specialists that includes neurologists, physiatrists, orthopedic surgeons, and physical and occupational therapists.

Depending on the individual's signs and symptoms, the following may be indicated:[1]
  • Special shoes, including those with good ankle support
  • Ankle/foot orthoses (AFO) to correct foot drop and aid with walking
  • Orthopedic surgery to correct severe pes cavus
  • Forearm crutches or canes for stability (fewer than 5% of affected individuals need wheelchairs)
  • Treatment of sleep apnea or restless legs
  • Treatment of pain and depression as needed
Last updated: 8/1/2012

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

  • To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by the American College of Medical Genetics and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.
  • The Muscular Dystrophy Association can help you find a doctor who knows about Charcot-Marie-Tooth disease. Click on the link to search for specialty clinics nearest you.
  • Services to enhance mobility and independent living are available in each community through the Muscular Dystrophy Association's local network of chapters and field offices. Click here to read more about this service.
  • The Muscular Dystrophy UK provides information regarding the Joseph Patrick Trust which provides financial support for specialist equipment. Click on the link to read more about this trust.
  • The Neuropathy Association has a Physicians Directory that lists neurologists and other physicians with expertise or expressed interest in caring for patients with peripheral neuropathy. This list is provided by The Neuropathy Association as a service to its members who have difficulty in locating a physician in their area who is knowledgeable about peripheral neuropathy and neuropathy treatment options. To search The Neuropathy Association's Physician Directory, click here.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Patient Registry

  • The Inherited Neuropathies Consortium is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with Charcot Marie Tooth disease through research. The Inherited Neuropathies Consortium has a registry for patients who wish to be contacted about clinical research opportunities.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Charcot-Marie-Tooth disease type 2F. This website is maintained by the National Library of Medicine.
  • The Muscular Dystrophy Association has developed an information page entitled "Surgery Sometimes, Bracing Often, Caution Always: Caring for the CMT-affected Foot." Click on Muscular Dystrophy Association to view this information page.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Charcot-Marie-Tooth disease type 2F. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Thomas D. Bird. Charcot-Marie-Tooth Neuropathy Type 2. GeneReviews. July 5, 2012; http://www.ncbi.nlm.nih.gov/books/NBK1285/. Accessed 7/31/2012.
  2. HSPB1. Genetics Home Reference. January 2010; http://ghr.nlm.nih.gov/gene/HSPB1. Accessed 7/31/2012.