Charcot-Marie-Tooth Disease: What It Is and What Causes It

If you've heard the name Charcot-Marie-Tooth (often searched as Charcot Marie Tooth, or CMT) and aren't sure what it means, it's easy to feel overwhelmed. The name sounds like a single person, but it actually belongs to three physicians. The short answer: Charcot-Marie-Tooth disease is a group of inherited conditions that affect the peripheral nerves, the ones that carry signals between your spinal cord and your feet, legs, hands, and arms. It is passed down through families, it tends to develop gradually, and it is diagnosed and followed by a neurologist. Below, we'll explain what CMT is, what causes it, the common signs, how it's evaluated, and where a thorough nerve-focused evaluation can fit alongside medical care. This is educational and not a diagnosis.

Charcot-Marie-Tooth in Plain English

Peripheral nerves work like wiring. Each nerve fiber has a core that carries the signal and, in many fibers, an insulating coat called myelin that helps the signal travel quickly. In Charcot-Marie-Tooth disease, a change in a gene affects how those nerve cells are built or maintained. Over time, signals to the muscles and signals back from the skin can weaken or slow.

That's why CMT is considered a type of inherited peripheral neuropathy. It's sometimes called hereditary motor and sensory neuropathy, because it can affect both movement (motor) and sensation (sensory). It's usually slow-moving. Many people notice changes in the feet and lower legs first, with the hands and forearms involved later in some forms.

CMT is not the same as the more common neuropathies linked to blood sugar, alcohol, or vitamin shortages. If you want to see how the different categories compare, our guide to types of neuropathy explained simply is a helpful companion, and the peripheral neuropathy page gives the bigger picture.

Why Is It Called Charcot-Marie-Tooth?

The condition is named for the three doctors who first described it in the late 1800s: Jean-Martin Charcot and Pierre Marie in France, and Howard Henry Tooth in England. The "Tooth" is a surname, not a reference to teeth, which is a common point of confusion.

What Causes Charcot-Marie-Tooth Disease?

CMT is caused by changes, called mutations, in genes that help nerve cells carry signals. Researchers have linked many different genes to the condition, which is why there are several types. The two broad groups are often described this way:

• Demyelinating types, in which the insulating coat around the nerve is the main problem and signals travel more slowly.
• Axonal types, in which the nerve fiber itself is the main problem and signals are weaker.

There are also forms that follow different inheritance patterns. In some families, one affected parent can pass it on. In others, both parents carry a changed gene without symptoms. Some forms are linked to the X chromosome. And occasionally, a person is the first in their family to have a new gene change.

Because the cause is genetic, it isn't something a person did or didn't do. It isn't caused by diet, exercise, or lifestyle. That can be a relief for people who have wondered whether they were to blame.

Common Signs and Symptoms

Symptoms vary from person to person, even within the same family. They often begin in childhood, the teen years, or early adulthood, though some people don't notice anything until later. Things people commonly describe include:

• High foot arches, flat feet, or curled toes (hammertoes)
• Tripping, frequent ankle rolls, or a foot that seems to slap the floor when walking, which can be a sign of foot drop (see our post on foot drop and the peroneal nerve)
• Weakness in the lower legs and ankles, which makes running or climbing steps harder (muscle weakness is often the first thing people notice)
• Numbness, tingling, or reduced feeling in the feet and sometimes the hands (numbness in hands and feet)
• Poor balance and a feeling of unsteadiness (balance problems)
• Thin-looking lower legs over time as muscles lose strength
• Trouble with fine tasks such as buttoning clothes, when the hands are affected

Because many of these also appear in other conditions, we can't tell anyone they have CMT from a list. That is exactly why a proper workup matters.

How Is Charcot-Marie-Tooth Diagnosed?

Diagnosis is made by a neurologist, often with help from a genetic specialist. The process usually includes several pieces:

1. Family history. Relatives with similar foot shape, walking changes, or numbness are an important clue, though some people have no known family history.
2. A neurological exam. Strength, reflexes, sensation, balance, and foot structure are checked.
3. Nerve conduction studies and EMG. These tests measure how fast and how well signals travel, and can help tell demyelinating from axonal patterns. Our post on what to expect from a nerve conduction test walks through it.
4. Genetic testing. A blood test can often identify the gene involved, which helps classify the type.

For a broader look at how nerve problems are sorted out, see how neuropathy is diagnosed.

Is Charcot-Marie-Tooth Disease Fatal?

This is one of the most common questions people type into search engines, and it deserves a calm answer. CMT is generally not considered a condition that shortens life, because it mainly affects the peripheral nerves rather than vital organs. Still, it is a lifelong condition, and the way it shows up depends heavily on the type. Some rare or severe forms can affect other functions, which is why your neurologist is the right person to speak about your particular type and what to watch for.

Where a Nerve-Focused Evaluation Can Fit

We want to be clear and honest here. Charcot-Marie-Tooth is a genetic condition, and no clinic, including ours, can change a person's genes. Diagnosis and long-term medical oversight belong with a neurologist, and many people also work with physical therapists and foot and ankle specialists for braces, orthotics, and safe movement.

What we can offer at The Roots Neuropathy in Lakewood Ranch is a thorough look at how your nerves and body are functioning right now, so you leave with a clearer picture and a plan to discuss with your care team. That includes a neuropathy evaluation with a 16-point sensory exam and balance test, and balance testing to look at stability and fall risk, which matters for anyone with ankle weakness or reduced foot sensation. Where it makes sense, our neuropathy program supports overall nerve and circulation health with an individualized approach. Each person is different, so we explain what we find and what it may mean in everyday language, and we refer you back to your neurologist whenever that's the right next step.

Everyday Habits Many People With CMT Find Useful

These are general ideas, not medical instructions, so check them with your own care team:

• Wear supportive, well-fitting shoes, and ask a specialist about ankle or foot supports.
• Look at your feet daily, since reduced sensation can hide small sores or blisters.
• Keep walking areas at home well lit and free of loose rugs and clutter.
• Stay active in ways your care team recommends, and avoid pushing through unusual fatigue.
• Pay attention to balance, especially on uneven ground and stairs.

Our article on fall-proofing your home with neuropathy has more practical ideas.

Frequently Asked Questions

What is Charcot-Marie-Tooth disease?

It's a group of inherited conditions that affect the peripheral nerves, often causing weakness, changes in foot shape, and reduced sensation, usually starting in the feet and lower legs.

Why is it called Charcot-Marie-Tooth?

It's named for three physicians who described it: Jean-Martin Charcot, Pierre Marie, and Howard Henry Tooth. The name has nothing to do with teeth.

What causes Charcot-Marie-Tooth disease?

Changes in genes that help nerve cells carry signals. It's inherited in most cases, though a new gene change can also occur in someone with no family history.

Is Charcot-Marie-Tooth disease fatal?

It is generally not considered life-shortening, but it is lifelong and varies by type. Your neurologist can speak to your specific form.

Can I be evaluated if I only suspect CMT?

A neurologist makes the diagnosis. A nerve-focused evaluation can help document your symptoms, strength, sensation, and balance so you have clearer information to bring to that appointment.

Get Clear Answers About Your Nerves

Whether you're trying to understand a family history, new foot changes, or numbness that doesn't add up, you deserve a real conversation about what's going on. Schedule your consultation and our team will take the time to listen.