Rare Primary Care News

Disease Profile

Charcot-Marie-Tooth disease type 1A

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.

1-5 / 10 000

US Estimated

Europe Estimated

Age of onset






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.


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.


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)

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


Congenital and Genetic Diseases; Nervous System Diseases; RDCRN


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]


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]

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:
30%-79% of people have these symptoms
Decreased motor nerve conduction velocity
Decreased sensory nerve conduction velocity
Distal muscle weakness
Weakness of outermost muscles
Distal sensory impairment
Decreased sensation in extremities
Decreased reflex response
Decreased reflexes

[ more ]

Pes cavus
High-arched foot
Sensory ataxia
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting

[ more ]

5%-29% of people have these symptoms
Acute demyelinating polyneuropathy
Calf muscle hypertrophy
Increased size of calf muscles
Diaphragmatic weakness
Weak diaphragm
Gait imbalance
Abnormality of balance
Abnormality of equilibrium
Imbalanced walk

[ more ]

Pins and needles feeling

[ more ]

Shoulder pain
Spontaneous pain sensation
1%-4% of people have these symptoms
Hyperactive deep tendon reflexes
Percent of people who have these symptoms is not available through HPO
Absent tendon reflexes
Autosomal dominant inheritance
Cold-induced muscle cramps
Decreased number of peripheral myelinated nerve fibers
Distal amyotrophy
Distal muscle wasting
Foot dorsiflexor weakness
Foot drop
Hammer toe

[ more ]

Hearing impairment
Hearing defect

[ more ]

Hypertrophic nerve changes
Insidious onset
Gradual onset
Juvenile onset
Signs and symptoms begin before 15 years of age
Limb muscle weakness
Limb weakness
Myelin outfoldings
Onion bulb formation
Peripheral neuropathy
Segmental peripheral demyelination/remyelination
Slow progression
Signs and symptoms worsen slowly with time
Split hand
Claw hand
Claw hand deformities
Claw hands
Claw-hand deformities

[ more ]

Steppage gait
High stepping
Ulnar claw
Variable expressivity


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

    Organizations Providing General Support

      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.
      • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
      • MedlinePlus Genetics contains information on Charcot-Marie-Tooth disease type 1A. This website is maintained by the National Library of Medicine.
      • 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.


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

          Rare Primary Care News

          fascinating Rare disease knowledge right in your inbox
          Subscribe to receive