KAREN Butcher laughs when she relates how little people know about the condition she has had since birth – Charcot-Marie-Tooth Syndrome.

“Nobody has ever heard of it. Quite often they’ll say ‘is there something wrong with your teeth?’ The name doesn’t help, but it happens to be named after the three doctors who discovered it.

“In many ways, CMT is a secret condition. It’s never spoken about and few people know it exists,” she adds.

“There’s a general lack of awareness in the medical profession, so people fail to be diagnosed quickly enough, meaning that many endure painful limbs, falling over and balance problems for many years.”

In fact CMT, also known as peroneal muscular atrophy and hereditary motor and sensory neuropathy, is the most common inherited nervous system disorder in the world, affecting up to one in every 2,500 people.

The progressive incurable disease leads to a loss of muscle tissue and touch sensation, mainly in the feet and legs, but also in the hands and arms of people in the advanced stages.

Symptoms and the speed at which CMT progresses vary. Common effects are abnormal curvature of the spine and foot problems. More rarely, breathing can be affected.

Karen, 47, of Christchurch, says: “I’ve always known I had CMT from when I was quite small. My family has a long history of it. I wasn’t really affected until I was between eight and 10. I didn’t fear it and it never bothered me in the least.”

She had her first operation when she was about 13 and has had further surgery at intervals throughout her life.

“Despite that I’m still reasonably mobile and my hands aren’t severely affected.

“There are things that can help – physiotherapy is very good at keeping muscles working, and you can use things such as splints to support the ankles.”

Karen underwent genetic counselling and knew that if she had babies, the chances of passing the disease on to them were 50:50.

“It’s a very personal decision. I always wanted to have children and was prepared to take the risk. Some people feel it’s wrong to spread their defective genes around, but it’s not that bad,” she says.

“My mum has never let it stop her doing anything. She’s now in her early seventies and has more problems with mobility, but she’s a good role model.”

Karen’s daughter, now 18, and 13-year-old son both have CMT, but so far her son has shown no symptoms.

“My daughter never walked normally, right from the word go. She started having physio as a three-year-old and has gone through a range of different splints.

“Surgery worked very well and she doesn’t let it bother her. The one thing that annoyed her was not being able to wear high heels.”

Karen runs the charity CMT UK from an office in Southbourne, Bournemouth. It has around 1,700 members around the country, but there could be as many as 23,000 sufferers.

“Most people are very positive. CMT can be extremely variable, from being mildly affected to having a major disability. Our chairman Lisa Welsh hasn’t walked since she was 16 and uses a ventilator at night,” says Karen.

Consultant neurologist Dr Mary Reilly said: “It is important to determine exactly what kind of CMT someone has in order to improve their quality of life.

“This can be done fairly easily, however this sort of assessment can only be done once the diagnosis is considered in a patient, which, based on research by CMT UK, is taking longer than we would hope.

“Many people put up with CMT for a long time thinking they are clumsy or have funny feet, suffering in silence when they could be receiving help and support.”

• CMT UK offers advice, information and support. To find out more see cmt.org.uk or email info@cmtuk or ring 01202 432048.