Little Joanne Evans struggles on crutches to the ballet class she loves and then throws them away as she battles so bravely to be like her friends. But sadly she'll always be different. For Joanne has almost stopped growing.
The mischievous strawberry blonde is 11 years old but she is no bigger than a four-year-old. She stands just 3ft tall - a good foot shorter than her classmates - and weighs two-and-a-half stone.
In the past year she has grown just half a centimetre - one-fifth of an inch.
It's all come as a tremendous shock for her mum Judy and dad Graham, who had no idea of the time-bomb ticking away inside their beloved first born.
Joanne was a normal baby who grew into a lively toddler, loved dancing and started ballet classes before she was three.
"Joanne was perfect. She had a really bubbly character and she was like a little blonde doll," said Judy. "But when she was three I noticed other toddlers in her playgroup were growing much faster.
"Then one day in autumn I pulled out her previous year's winter clothes. Straight away I knew something was wrong.
"I was prepared to have to buy all new things for her. You expect them to shoot up at that age but instead all last year's clothes fitted Joanne perfectly. She had hardly grown at all."
The local health clinic tried to reassure Judy that her daughter was just small for her age. "But I knew something was wrong. I suppose it was mother's instinct," said Judy, 47. Finally their GP referred them to the local hospital for tests. X-rays on Joanne's wrist bones showed abnormalities and then blood tests revealed the awful truth. Joanne had inherited a rare and incurable genetic disease called Morquio's Syndrome.
"I couldn't come to terms with it," admits Judy, from Bridge of Weir, 15 miles outside Glasgow. "Imagine how we felt when we knew what we had passed on to our child.
"I didn't want anything to do with anyone. I couldn't bear to read anything about Joanne's condition for 18 months. I was devastated. It's your worse nightmare. When there's something wrong with your baby, you think someone can fix it but with Morquio's Syndrome there are no medicines, no treatments. You feel so helpless.
"We decided not to have any more children. There's a one-in-four chance of passing on the gene again. It wasn't fair to inflict that risk on another child.
"We also thought if we had another one then we would be dividing our time and wouldn't be able to give Joanne all the attention she needs. …