Charcot-Marie-Tooth disease

Also called CMT, Hereditary motor and sensory neuropathy

The most common inherited neurological condition, and one most people have never heard of. Nothing to do with teeth.

What it is

An inherited condition damaging the peripheral nerves, those running from the spinal cord to the limbs. It affects roughly 1 in 2,500 people, making it the commonest inherited neurological disorder in the UK.

The name comes from the three doctors who described it. It has nothing to do with teeth, which is a source of endless confusion and is worth saying first.

The nerves supplying the feet and lower legs are affected earliest and worst, then the hands. It causes weakness, wasting, altered sensation and characteristic foot shape: a high arch and clawed toes.

It usually progresses slowly over decades. Most people keep walking, many with orthotics, and life expectancy is normal in the common types.

There is no cure and no disease-modifying treatment, so everything worthwhile is management: physiotherapy, occupational therapy, podiatry and orthotics. Done well, they change function substantially.

Certain medicines, including some chemotherapy drugs, can worsen it, and there is a published list worth carrying.

Signs you might notice

High arches and clawed toes, often noticed in childhood or adolescence.

Frequent tripping, ankle sprains and falls, from weak ankle muscles and foot drop.

Difficulty running, and being the last picked at school long before anybody thought of a diagnosis.

Weakness and wasting of the lower legs, giving an inverted-champagne-bottle shape.

Later: weak hands, difficulty with buttons, jars and keys.

Reduced sensation in the feet and hands, and sometimes nerve pain.

Fatigue, which is prominent and consistently under-recognised.

A family history, though new mutations happen and some types are recessive.

How it can affect day-to-day life

Fatigue is the symptom people rate highest and clinicians ask about least. Walking with weak, poorly controlled feet costs far more energy than it looks.

Feet need careful attention: reduced sensation plus deformity means pressure damage, and it can go unnoticed. See podiatry.

Ankle-foot orthoses transform walking for many people and are frequently offered late, badly fitted, or abandoned because nobody explained how to wear them in.

The hands go later and matter more than expected: buttons, zips, cutlery, keys. Occupational therapy and simple aids make a large difference.

Because it is slowly progressive and rarely dramatic, people often get no follow-up at all, and pick up problems only when something has already gone wrong.

Supporting someone well

Ask for a neuromuscular centre rather than general neurology, and for genetic testing to identify the type, which affects what to expect.

Ask for orthotics assessment early rather than after repeated falls, and persist if the first pair does not work.

Check the feet daily. Reduced sensation plus a high arch means pressure damage without pain.

Ask for physiotherapy focused on maintaining range and balance, and occupational therapy for hands and daily tasks.

Carry the list of medicines that can worsen neuropathy and show it before any chemotherapy or new prescription.

Ask about fatigue management, and pace rather than push.

Ask about genetic counselling for the family.

Where to get help

A GP practice for referral to neurology, ideally a neuromuscular service.

CMT UK are the specialist charity and hold the medicines-to-avoid list.

Muscular Dystrophy UK for equipment, benefits and support.