How Common Is Charcot-Marie-Tooth Disease?

Charcot-Marie-Tooth disease (CMT) affects roughly 1 in 5,000 to 6,000 people worldwide, making it the most common inherited disorder of the peripheral nerves. A large meta-analysis pooling studies from multiple countries estimated the prevalence at about 17.7 per 100,000 people.¹ That number, though, hides wide geographic variation and a striking pattern: recorded cases have been climbing sharply in recent decades, mostly because doctors are getting better at recognizing the condition rather than because more people are developing it.

Why Prevalence Numbers Differ So Much by Country

If you look at prevalence figures from individual countries, the spread is wide enough to seem like researchers are studying different diseases. Studies have estimated that roughly 1 in 9,200 people in Japan, 1 in 8,300 in Iceland, 1 in 5,700 in Italy, and 1 in 3,500 in Spain have CMT.² A population-based study in New Zealand found a prevalence of about 15.7 per 100,000 after adjusting for age, translating to about 1 in every 6,369 people.³ Meanwhile, UK primary-care data from 2019 put the figure as high as 29.5 per 100,000.⁴

Some of this variation reflects real genetic differences between populations. In East Asian populations, for instance, mutations in genes like GDAP1, MPZ, and GJB1 appear more frequently than in European cohorts.⁵ But most of the spread comes from how each study was conducted. Countries with robust neurology referral networks and genetic testing infrastructure catch more cases. Countries where milder CMT goes undiagnosed or gets lumped in with “idiopathic neuropathy” report lower numbers. The older, commonly cited figure of 1 in 2,500 comes from studies that screened populations aggressively, and some researchers consider it closer to the true figure once subclinical and undiagnosed cases are included.⁶

Diagnosis Rates Are Rising Fast, but the Disease Is Not New

One of the most striking trends in CMT epidemiology is how steeply diagnosis rates have climbed. In the UK, the recorded prevalence of CMT more than doubled between 2000 and 2019, rising from 12.3 to 29.5 per 100,000, a 139% increase. Incidence rose 48% over the same period.⁴ Denmark saw an even more dramatic jump: the recorded incidence increased by a factor of 4.4 between 1988 and 2012.⁷

This does not mean CMT is becoming more common in any biological sense. The mutations that cause it are inherited and have been present in human populations for a long time. What changed is awareness and diagnostic capability. Genetic testing for CMT expanded enormously over the past two decades, and clinicians became more familiar with the condition’s presentation. People who 30 years ago would have been told they had “weak ankles” or an unexplained neuropathy now receive an accurate genetic diagnosis. The rising numbers are largely a measurement effect, not an epidemic.

Which Genetic Subtypes Are Most Common

CMT is not one disease but a family of conditions caused by mutations in dozens of different genes, all of which damage the peripheral nerves. In practice, though, a handful of subtypes account for the vast majority of cases. The most common form, CMT1A, is caused by a duplication of the PMP22 gene and makes up about 40% of all CMT cases.³ After CMT1A, the next most frequently identified subtypes are CMT1X (caused by mutations in GJB1), hereditary neuropathy with liability to pressure palsies (HNPP, also involving PMP22), CMT1B (MPZ gene), and CMT2A (MFN2 gene). Everything else is individually rare, with each additional subtype accounting for less than 1% of diagnosed cases.⁸

When genetic testing successfully identifies a cause, mutations in just four genes (PMP22, GJB1, MPZ, and MFN2) explain over 90% of confirmed diagnoses.⁹ This concentration is useful for diagnostic strategy: testing for these four genes first catches most cases. But it also means that the remaining patients, whose mutations fall in less common genes, often face a longer and more frustrating diagnostic journey.

Many People Wait Years for the Right Diagnosis

CMT is common enough that neurologists encounter it regularly, yet misdiagnosis remains a serious problem. A German patient survey found that over half of respondents had received a wrong diagnosis at least once before being correctly identified with CMT. Among those who were initially misdiagnosed, the median delay to a correct diagnosis stretched to 9 years for patients with one prior wrong diagnosis and 18 years for those with multiple misdiagnoses. About 30% of patients who had been misdiagnosed reported receiving inappropriate treatments as a result, and the majority of those felt the wrong therapy caused lasting harm to their health.¹⁰

Children face their own version of this delay. In pediatric cases where there was no known family history of CMT, parents first noticed symptoms at an average age of about 5.6 years, but the clinical diagnosis did not arrive until around age 9.3, and genetic confirmation followed at about 10.3 years. When a family history was known, the timeline was somewhat faster but still not immediate: symptoms noticed around age 3.7, clinical diagnosis at 7.2, genetic confirmation at 8.¹¹ These gaps matter because early interventions like physical therapy and orthotics can slow functional decline.

What Genetic Testing Can and Cannot Do

Genetic testing has transformed CMT diagnosis, but it does not solve every case. When clinicians use targeted gene panels covering the most common CMT-related genes, about 30% of previously undiagnosed patients receive a definitive answer. Mutations in GJB1, MFN2, and MPZ accounted for about 39% of those confirmed cases, with the rest spread across less common genes.¹² A Brazilian study found a similar diagnostic yield: after a stepwise approach starting with testing for the PMP22 duplication and then moving to broader panels, about 36% of patients who underwent panel testing received a confirmed genetic diagnosis.¹³

Whole genome sequencing pushes the diagnostic rate somewhat higher but not as dramatically as you might expect. In a large UK cohort of 233 CMT patients enrolled in the 100,000 Genomes Project, whole genome sequencing contributed to a diagnosis in about 32% of cases overall, though a meaningful share of those diagnoses were made through manual research analysis of the data rather than through the automated reporting pipeline.¹⁴ That means a substantial minority of people with clinically typical CMT still cannot get a genetic confirmation. They carry mutations in genes that have not yet been associated with the disease, or their mutations are in hard-to-detect regions of known genes.

A confirmed genetic diagnosis helps more than you might think beyond simple labeling. It can guide family planning, predict disease trajectory to some extent, and determine eligibility for emerging clinical trials that target specific gene products. For the patients left without one, the clinical diagnosis remains valid, but the uncertainty can be frustrating.

When Symptoms Typically Begin

CMT usually makes itself known in childhood or adolescence, though the timing depends heavily on the genetic subtype. In a pediatric cohort, the mean age at symptom onset was 3.6 years, with a mean age at diagnosis of 7.7 years.¹⁵ The demyelinating forms (like CMT1A), which damage the insulating layer around nerves, tend to declare themselves earlier, with a mean age at diagnosis of about 7.9 years. The axonal forms, which damage the nerve fibers themselves, show up later on average, around age 12.7.¹⁵

CMT2A, one of the more severe axonal forms, follows a similar pattern: most patients with the autosomal dominant and autosomal recessive forms first noticed symptoms in their first two decades of life, often as trouble walking or keeping balance.¹⁶ The hallmark early signs tend to be a high-arched foot, frequent tripping, and ankle weakness. Pes cavus, the high-arched foot deformity, is considered an early and age-dependent feature of CMT1A specifically.¹⁷ In some families, these foot changes are the reason anyone sees a doctor in the first place.

Disease progression in children is measurable even over short periods. A longitudinal study of Brazilian children and adolescents with CMT found that scores on a pediatric disease severity scale increased by about 4.5 points over two years, with meaningful deterioration visible within just one year in areas like hand dexterity, sensation, and gait.¹⁸

Subclinical Carriers and People Who Never Know They Have It

Not everyone who carries a CMT-causing mutation develops obvious symptoms. This is especially true for women who carry X-linked forms of the disease (CMTX1). In one study of four families with GJB1 mutations, eight female carriers had no clinical symptoms at all, yet five of those eight showed signs of nerve damage when tested with electrophysiology.¹⁹ These people are technically affected but may go through life with no idea they carry the gene.

Asymptomatic carriers are not limited to X-linked forms. A study of CMT type 2CC, caused by NEFH gene variants, identified 3 asymptomatic mutation carriers among 33 people who had the mutation across eight families.²⁰ Other families with GJB1 mutations have shown phenotypes ranging from no symptoms at all to moderate disability, even among relatives carrying the same genetic change.²¹

The existence of subclinical carriers means that true prevalence is almost certainly higher than any figure based on clinical diagnosis. How much higher is genuinely unknown, because you would need to genetically screen an entire population to find out, and no study has done that on a large scale. This is one reason estimates in the literature range from 1 in 2,500 at the aggressive end to 1 in 10,000 at the conservative end.

How X-Linked CMT Affects Women Differently

CMTX1, caused by GJB1 mutations, is the second most common form of CMT overall, and it behaves differently in men and women because the gene sits on the X chromosome. Men, who have only one X, tend to develop symptoms earlier and progress more rapidly. A large cross-sectional study found that the nerve damage measured by both clinical severity scores and electrophysiology was consistently worse in men than in women.²²

But “milder” does not mean “absent.” A study of 137 women and 126 men with CMTX1 found that women often had more asymmetric weakness, affecting one side of the body more than the other. After about age 48, two distinct groups of women emerged: roughly 55% progressed to disability levels comparable to men, just with a later onset, while the remaining women stayed mildly affected or symptom-free.²³ About 39% of the women in that study had a particular nerve conduction abnormality called motor conduction block, which can be mistaken for an autoimmune neuropathy. Four women had actually received immunoglobulin infusions for a suspected autoimmune condition before anyone realized the underlying cause was genetic.²³

The natural history data underscores the sex difference: in a genetic analysis tracking disease burden over time, male disease severity correlated strongly with age, while the correlation in women was much weaker and more variable.²⁴ For women carrying a GJB1 mutation, predicting how the disease will unfold over a lifetime is considerably harder than for men.

Life Expectancy and Mortality

CMT is not typically described as a life-threatening condition, and most people with it live into old age. But a nationwide study from South Korea found that mortality was moderately elevated: the standardized mortality ratio across all CMT patients was about 1.57, meaning CMT patients died at roughly one and a half times the rate of the general population. The excess risk was highest in young children (under age 9) and declined with age, with no significant difference between men and women.²⁵ The elevated mortality in childhood likely reflects the most severe early-onset subtypes, including some recessive forms that can cause profound disability.

For the majority of people living with the more common subtypes like CMT1A, the disease is disabling but not typically fatal. It progresses slowly over decades. Most people remain ambulatory, though many eventually need ankle-foot orthoses or other bracing. In one clinical cohort, about 5% of patients needed a cane, and roughly 4% required a walker or wheelchair.²⁶

The Financial Burden of a “Mild” Genetic Disease

Because CMT progresses slowly and rarely leads to hospitalization, it can be easy to underestimate the economic toll it takes. A cost-of-illness analysis in Germany estimated total annual costs of about $22,000 per patient, with roughly two-thirds of that going to direct medical costs like rehabilitation, orthotics, and specialist visits. The single largest expense was informal care, the unpaid help provided by family members. Extrapolated across the German CMT population, the total cost was estimated at roughly $735 million annually. Costs scaled steeply with disease severity.²⁷

These numbers highlight a tension in how CMT is perceived. From a purely medical standpoint, it is often classified as a “benign” inherited neuropathy because it does not kill most people or put them in the ICU. From the patient’s perspective, the reality is decades of progressive weakness, hand dysfunction, chronic pain in many cases, career limitations, and reliance on devices and family support. The fact that it is the most common inherited neuropathy means those costs, multiplied across hundreds of thousands of affected people worldwide, add up to a significant public health burden that tends to fly under the radar compared to rarer but more dramatic genetic diseases.

The Foot Changes That Often Lead to Diagnosis

If you have CMT and do not know it yet, the likeliest reason you will end up in a doctor’s office is your feet. The gradual weakening of the small muscles in the foot causes the arch to rise over time, pulling the foot into a high-arched, inward-turned shape known as cavovarus foot. This is considered the defining orthopedic feature of CMT and affects the great majority of patients.²⁸ The foot deformity is not present at birth; it develops as the disease-related nerve damage causes an imbalance between the muscles that pull the foot up and those that point it down.

For orthopedic surgeons and podiatrists, an adult who shows up with bilateral high arches and thin calves should immediately raise the question of an underlying hereditary neuropathy. Yet this connection is still missed more often than it should be. Some patients go through years of ankle sprains, foot surgery, and custom orthotics before anyone thinks to check for CMT. The fact that foot changes are age-dependent and worsen gradually means that a child examined at age five may have a relatively normal-looking foot, while the same child at fifteen has a classically cavovarus shape that any neuromuscular specialist would recognize.

1
PubMed. A meta-analysis on the prevalence of Charcot-Marie-Tooth disease and related inherited peripheral neuropathies
2
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3
PubMed Central. Prevalence of Charcot-Marie-Tooth disease across the lifespan: a population-based epidemiological study
4
PLOS ONE. Prevalence and incidence of neuromuscular conditions in the UK between 2000 and 2019: A retrospective study using primary care data
5
PubMed Central. Clinical and Genetic Variant Profile of Asian Charcot-Marie Tooth Patients: A Systematic Review
6
PubMed Central. PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies
7
BMJ Open. Charcot-Marie-Tooth disease in Denmark: a nationwide register-based study of mortality, prevalence and incidence
8
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9
Journal of Neurology, Neurosurgery & Psychiatry. Charcot–Marie–Tooth disease: frequency of genetic subtypes and guidelines for genetic testing
10
PubMed Central. Patient journey with Charcot-Marie-Tooth Disease – A German patient survey study
11
MDA Conference. Diagnostic Dilemma in Pediatric CMT
12
PubMed Central. Targeted next-generation sequencing panels in the diagnosis of Charcot-Marie-Tooth disease
13
PubMed Central. High diagnostic yield with algorithmic molecular approach on hereditary neuropathies
14
PubMed Central. Whole genome sequencing increases the diagnostic rate in Charcot-Marie-Tooth disease
15
PubMed Central. Pediatric Cohort of Charcot-Marie-Tooth Disease Clinical Features and Genetic Distribution
16
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17
PubMed. New insights into the pathophysiology of pes cavus in Charcot-Marie-Tooth disease type 1A duplication
18
PubMed Central. Longitudinal assessment of natural disease progression in Brazilian children and adolescents with Charcot-Marie-Tooth disease
19
Journal of the Neurological Sciences. X-linked dominant Charcot–Marie–Tooth neuropathy: clinical, electrophysiological, and morphological phenotype in four families with different connexin32 mutations
20
Journal of Neurology, Neurosurgery & Psychiatry. Charcot-Marie-Tooth disease type 2CC due to NEFH variants causes a progressive, non-length-dependent, motor-predominant phenotype
21
PubMed. Clinical, electrophysiological and molecular genetic studies in a family with X-linked dominant Charcot-Marie-Tooth neuropathy presenting a novel mutation in GJB1 Promoter and a rare polymorphism in LITAF/SIMPLE
22
PubMed Central. Cross-sectional analysis of a large cohort with X-linked Charcot-Marie-Tooth disease (CMTX1)
23
PubMed. Clinical and electrophysiological characteristics of women with X-linked Charcot-Marie-Tooth disease
24
Brain. Genetic analysis and natural history of Charcot-Marie-Tooth disease CMTX1 due to GJB1 variants
25
PubMed. Prevalence, Mortality, and Cause of Death in Charcot-Marie-Tooth Disease in Korea: A Nationwide, Population-Based Study
26
PubMed Central. Charcot-Marie-Tooth neuropathy score and ambulation index are both predictors of orthotic need for patients with CMT
27
PubMed. Cost of illness in Charcot-Marie-Tooth neuropathy: Results from Germany
28
PubMed Central. ACQUIRED PES CAVUS IN CHARCOT-MARIE-TOOTH DISEASE