Charcot-Marie-Tooth disease type 1A

Información en español Title

Other Names:

Charcot-Marie-Tooth disease, demyelinating, type 1A; CMT 1A; Hereditary motor and sensory neuropathy 1A; Charcot-Marie-Tooth disease, demyelinating, type 1A; CMT 1A; Hereditary motor and sensory neuropathy 1A; HMSN 1A; Charcot Marie Tooth disease type 1A See More

Categories:

Congenital and Genetic Diseases; Nervous System Diseases; RDCRN

This disease is grouped under:

Charcot-Marie-Tooth disease; Charcot-Marie-Tooth disease type 1

Summary Summary

Charcot-Marie-Tooth disease type 1A (CMT1A) is a type of inherited neurological disorder that affects the peripheral nerves. People with this disease experience weakness and wasting (atrophy) of the muscles of the lower legs beginning in adolescence; later they can also have hand weakness and sensory loss.^[1] In CMT1A, abnormal nerve conduction studies can be found in babies or toddlers, but the symptoms that are characteristic of the disease may not occur until 20 years of age or later.^[2] CMT1A is caused by having an extra copy (a duplication) of the PMP22 gene.^[1]^[2] It is inherited in an autosomal dominant manner. Treatment for this condition may include physical therapy; occupational therapy; braces and other orthopedic devices; orthopedic surgery; and pain medications.^[1] The severity and degree of disability varies very much among the affected people.^[2]

Last updated: 4/17/2018

Symptoms Symptoms

Usually, people with CMT1A are slow runners in childhood, can develop high arches and hammertoes and often require the use of braces for ankle support. They may have hand weakness, that appear about 10 years after foot and leg problems. Problems with balance because of ankle weakness and loss of proprioception (the brain’s ability to know where the limbs are in space) are common. Most patients (95 percent) remain ambulatory throughout their lives and life expectancy is normal.^[2]^[3]

Last updated: 4/17/2018

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	Learn More: HPO ID
30%-79% of people have these symptoms
Decreased motor nerve conduction velocity		0003431
Decreased sensory nerve conduction velocity		0003448
Distal muscle weakness	Weakness of outermost muscles	0002460
Distal sensory impairment	Decreased sensation in extremities	0002936
Hyporeflexia	Decreased reflex response Decreased reflexes [ more ]	0001265
Pes cavus	High-arched foot	0001761
Sensory ataxia		0010871
Skeletal muscle atrophy	Muscle degeneration Muscle wasting [ more ]	0003202
5%-29% of people have these symptoms
Acute demyelinating polyneuropathy		0007131
Calf muscle hypertrophy	Increased size of calf muscles	0008981
Diaphragmatic weakness	Weak diaphragm	0009113
Gait imbalance	Abnormality of balance Abnormality of equilibrium Imbalanced walk [ more ]	0002141
Kyphoscoliosis		0002751
Paresthesia	Pins and needles feeling Tingling [ more ]	0003401
Shoulder pain		0030834
Spontaneous pain sensation		0010833
1%-4% of people have these symptoms
Hyperactive deep tendon reflexes		0006801
Percent of people who have these symptoms is not available through HPO
Areflexia	Absent tendon reflexes	0001284
Autosomal dominant inheritance		0000006
Cold-induced muscle cramps		0003449
Decreased number of peripheral myelinated nerve fibers		0003380
Distal amyotrophy	Distal muscle wasting	0003693
Foot dorsiflexor weakness	Foot drop	0009027
Hammertoe	Hammer toe Hammertoes [ more ]	0001765
Hearing impairment	Deafness Hearing defect [ more ]	0000365
Hypertrophic nerve changes		0003382
Insidious onset	Gradual onset	0003587
Juvenile onset	Signs and symptoms begin before 15 years of age	0003621
Limb muscle weakness	Limb weakness	0003690
Myelin outfoldings		0004336
Onion bulb formation		0003383
Peripheral neuropathy		0009830
Segmental peripheral demyelination/remyelination		0003481
Slow progression	Signs and symptoms worsen slowly with time	0003677
Split hand	Claw hand Claw hand deformities Claw hands Claw-hand deformities Split-hand [ more ]	0001171
Steppage gait	High stepping	0003376
Ulnar claw		0001178
Variable expressivity		0003828

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Do you have more information about symptoms of this disease? We want to hear from you.

Last updated: 2/1/2019

Do you have updated information on this disease? We want to hear from you.

Inheritance Inheritance

CMT1A is inherited in an autosomal dominant manner.^[2] This means that having a change (mutation) in only one copy of the responsible gene in each cell is enough to cause features of the condition.

In some cases, an affected person inherits the mutated gene from an affected parent. In other cases, the mutation occurs for the first time in a person with no family history of the condition. This is called a de novo mutation.

When a person with a mutation that causes an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit that mutation.

Last updated: 1/10/2017

Find a Specialist Find a Specialist

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 Campaign provides information regarding the Joseph Patrick Trust which provides financial support for specialist equipment. Click on the link to read more about this trust.

Research Research

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.

Clinical Research Resources

ClinicalTrials.gov lists trials that are related to Charcot-Marie-Tooth disease type 1A. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.
The Research Portfolio Online Reporting Tool (RePORT) provides access to reports, data, and analyses of research activities at the National Institutes of Health (NIH), including information on NIH expenditures and the results of NIH-supported research. Although these projects may not conduct studies on humans, you may want to contact the investigators to learn more. To search for studies, enter the disease name in the "Text Search" box. Then click "Submit Query".

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.

Organizations 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: 800-606-2682
Telephone: 610-499-9264
Fax: 610-499-9267
E-mail: info@cmtusa.org
Website: http://www.cmtausa.org/
Charcot-Marie-Tooth Association Australia Inc.
Building 22
Concord Hospital
Concord, NSW, 2139 Australia
Telephone: (02) 9767 5105
E-mail: cmtaa2@cmt.org.au
Website: https://www.cmt.org.au
CMT United Kingdom
3 Groveley Road
Christchurch, Dorset BH23 3HB
United Kingdom
Toll-free: 0800 6526312
Telephone: 01202 474203
E-mail: enquiries@cmt.org.uk
Website: http://www.cmt.org.uk
Hereditary Neuropathy Foundation Inc.
401 Park Avenue, 10th Floor
New York, NY 10016
Toll-free: 855-435-7268
Telephone: 212-722-8396
E-mail: info@hnf-cure.org
Website: http://www.hnf-cure.org/
Muscular Dystrophy Association (MDA)
222 S Riverside Plaza
Suite 1500
Chicago, IL 60606
Toll-free: 1-800-572-1717
TTY: 1-800-572-1717
E-mail: mda@mdausa.org
Website: http://www.mdausa.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: info@musculardystrophyuk.org
Website: http://www.musculardystrophyuk.org/

Do you know of an organization? We want to hear from you.

Learn More 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

Genetics Home Reference (GHR) contains information on Charcot-Marie-Tooth disease type 1A. 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.
MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.
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.
Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
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 1A. Click on the link to view a sample search on this topic.

News & Events News & Events

News

NIH Hosts Rare Disease Day Event, Twitter Chat
January 24, 2019
CMT1A Research Breakthrough!
December 6, 2017

GARD Answers GARD Answers

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. Submit a new question

My daughter's father was diagnosed with CMT1A in childhood. My daughter is very active and we decided to not have her tested, unless she shows symptoms. I have noticed that her hands sometimes shake. Should this be a concern? Also she walks on her tip toes. She has since she started walking. However I did too as a child and I don't have the disease. Her father has stated that he has never been physically able to walk on his toes even as a child. I read so many things on the internet and it's so confusing. Her feet do not look abnormal. Anyway I was just wondering about the toe walking and the hands shaking sometimes. See answer
Do people with CMT type 1A relapse or does the illness just progress to a more advanced stage? I am aware that it is progressive. I have not read or heard of relapses in this disease, but as it is similar to MS, wondered whether this is a possibility or whether the illness itself is progressing and I will therefore have to learn to accept it. I have experienced periods similar to this but never as extreme. See answer

Have a question? Contact a GARD Information Specialist.

References References

Charcot-Marie-Tooth Disease Fact Sheet. National Institute of Neurological Disorders and Stroke Website. May, 2017; http://www.ninds.nih.gov/disorders/charcot_marie_tooth/detail_charcot_marie_tooth.htm.
Bird TD. Charcot-Marie-Tooth Neuropathy Type 1. GeneReviews. March 26, 2015; http://www.ncbi.nlm.nih.gov/books/NBK1205/.
Francisco de Assis Aquino Gondim. Hereditary Neuropathies of the Charcot-Marie-Tooth Disease Type. Medscape Reference. 2014; http://emedicine.medscape.com/article/1173484-overview#a1.

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