By Jane Elliott
BBC News, health reporter
For years Camilla Le May suffered aches and pains in her left hand - no-one could pinpoint why.
Camilla Le May sculpts animals
From the age of 12 Camilla had a curious swelling in the middle and index fingers of the hand, which started curling up and stiffening.
Then the tendon in the middle of her palm started to thicken and protrude - and over the years the curling and thickening worsened.
She also started suffering pains ranging from dull aches to deep sharp pains. The pain became worse if she was run down or tired, too cold or too hot, or if she had been working too hard.
Continue to sculpt
Doctors were mystified.
Two years ago Camilla, now 34 and a sculptress, decided to have one more go at getting her condition resolved.
"I went to ask my doctor if I could have an operation to relieve the tension in my hand. When I was a child someone had said this might be a possibility if it continued.
"He said he could not operate without knowing what it was and ordered an X-ray. Luckily the radiologist had done a paper on melorheostosis (melo) and recognised it."
Specialists then confirmed that Camilla has the little-known progressive bone disease that affects her left hand and arm.
Camilla, from East Sussex, is only one of 17 people in the UK and 120 globally, to be diagnosed with melo. But there are fears there could be considerably more undiagnosed cases.
Melo causes serious pain, deformity and restrictive movement. It is thought to be most severe during the formative years, but can also cause problems as people age.
It is characterised by abnormal bone formation, which on X-ray makes the bones look as though they are coated with candle wax.
Because it is so rare Camilla's X-ray is often used in lectures on the condition.
Camilla, who creates animal sculptures which are sold internationally, said: "This diagnosis was concerning for me, as being a sculptor my work relies on my hands but very fortunately I am right handed, so I am able to continue sculpting mainly with my right unaffected hand.
"I think the worst time for me was when I was first diagnosed.
"Because it is so unknown I would trawl the internet trying to find information. The information left me scared - but what you need to remember is that it is different for everyone."
Camilla, who has won the Society of Wildlife Artists' bursary three years running, admits her condition can make finishing her bronze sculptures difficult, but says she has adapted to this.
She has had a supportive glove specially made to enable her to continue sculpting and she uses heat and bandages to help her ease the pain.
But says the fact that so little is known about the causes makes it difficult to know how her condition could progress.
"The hand feels very constricted but I am used to this. I am not able to use the left hand properly and as a result the muscles in this hand and wrist are wasted.
The X-rays show surplus bone formation
"I type with the right hand only and have found I have adapted to the disability without consciously thinking about it.
"I do not know what the problems will be as I get older.
"Anyone can get problems with their bones as they get older, but I have a problem to begin with."
When melo occurs on its own (the form known as sporadic melo, such as suffered by Camilla), it is not inherited.
But if the condition is coupled with a milder bone disorder called osteopoikilosis experts believe a gene critical to bone formation may play a role
More cases possible
The Melorheostosis Association, set up in 2005, is now trying to raise £500,000 to fund research into the disease's cause, treatment and cure.
Professor Paul Wordsworth, medical adviser to the Melorheostosis Association and consultant rheumatologist at the Nuffield Orthopaedic Centre, Oxford, said there is so much still to discover.
"We don't know a lot about it and there could still be some of the milder cases still hiding in the woodwork.
"Cases can vary from those who have an entire limb affected to those where just part of the limb is affected."
Camilla has an exhibition at the Lennox Gallery, 77 Moore Park Road, London, between October 2-7.