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Disease Profile
Charcot-Marie-Tooth disease type 2F
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
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Age of onset
Adolescent
ICD-10
G60.0
Inheritance
Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.
Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.
X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.
Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.
Not applicable
Other names (AKA)
CMT 2F; Charcot-Marie-Tooth disease, axonal, Type 2F; Charcot-Marie-Tooth disease, neuronal, Type 2F;
Categories
Congenital and Genetic Diseases; Nervous System Diseases
Summary
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
Symptoms
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]
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.
Medical Terms | Other Names |
Learn More:
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 |
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 |
Cause
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.
Diagnosis
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
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
Organizations
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
-
Charcot-Marie-Tooth Association
PO Box 105
Glenolden, PA 19036
Toll-free: 1-800-606-2682
Telephone: +1-610-499-9264
Fax: +1-610-499-9267
E-mail: [email protected]
Website: https://www.cmtausa.org/ -
Charcot-Marie-Tooth Association Australia Inc.
Building 22
Concord Hospital
Concord, NSW, 2139 Australia
Telephone: (02) 9767 5105
E-mail: [email protected]
Website: https://www.cmt.org.au -
Charcot-Marie-Tooth UK (CMT UK)
3 Groveley Road
Christchurch, Dorset BH23 3HB
United Kingdom
Telephone: 0300 323 6316
E-mail: [email protected]
Website: https://www.cmt.org.uk/ -
CMT Research Foundation
4062 Peachtree Road
Suite A209
Atlanta, GA 30319
Telephone: (404) 806-7180
E-mail: [email protected]
Website: https://cmtrf.org/ -
Hereditary Neuropathy Foundation Inc.
401 Park Avenue, 10th Floor
New York, NY 10016
Toll-free: 1-855-435-7268
Telephone: +1-212-722-8396
Fax: +1-917-591-2758
E-mail: [email protected]
Website: https://www.hnf-cure.org/
Organizations Providing General Support
-
Muscular Dystrophy Association (MDA)
222 S Riverside Plaza
Suite 1500
Chicago, IL 60606
Toll-free: 1-833-275-6321 (Helpline)
E-mail: [email protected]
Website: https://www.mda.org -
Muscular Dystrophy UK
61A Great Suffolk Street
London, SE1 0BU United Kingdom
Toll-free: 0800 652 6352 (Helpline)
Telephone: (+44) 0 020 7803 4800
E-mail: [email protected]
Website: https://www.musculardystrophyuk.org/
Learn more
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
- 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.
- Genetics Home Reference (GHR) contains information on Charcot-Marie-Tooth disease type 2F. This website is maintained by the National Library of Medicine.
- 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.
References
- Thomas D. Bird. Charcot-Marie-Tooth Neuropathy Type 2. GeneReviews. July 5, 2012; https://www.ncbi.nlm.nih.gov/books/NBK1285/. Accessed 7/31/2012.
- HSPB1. Genetics Home Reference. January 2010; https://ghr.nlm.nih.gov/gene/HSPB1. Accessed 7/31/2012.
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