As four-year-old Hayley Okines turns on her umpteenth smile for the photographer, she doesn't bat an eyelid.

The youngster is known throughout her home town of Sidley, near Bexhill, and will be a star to the rest of the nation when she appears in a TV documentary recounting her amazing story.

For Hayley has a very rare disease which makes her age eight years every 12 months.

She is only one of five people in Britain, and 100 worldwide, known to have ever suffered the condition.

A film crew has followed her from home, to playschool and even as far as America.

In the autumn, Extraordinary Lives will be screened on Channel Five. Her parents believe her time in front of the camera has been as big a boost as any medication.

Mark, 40, explained: "It has really helped Hayley being in the media. Channel Five contacted us about following her around and we thought it would be a good idea.

"They have been doing it for the last two months and she has loved every minute."

Being in the same room as Hayley, it is easy to see how her bounce and vitality is perfect for the big screen. Her impenetrable spirit masks her slight figure, thinning skin and virtually bald head.

Her parents Kerry Button and Mark Okines have tried desperately hard for their daughter to lead a normal existence.

As she ages quicker than normal, it means her internal organs, such as her heart and lungs, are at the same stage as someone aged 32.

The disease, progeria syndrome, has also caused external problems such as her veins to showing all over her body due to her very thin skin.

When Hayley was diagnosed in October 1999, Kerry, 28, fell into a depression and Mark had to give up his job as a carpenter.

Kerry said: "Before we knew what she had, I was always panicking about her. It is easy to tell that something is wrong now but back then she had a full head of hair and her nose and eyes were less protruding.

"When we eventually found out about the syndrome, our whole world fell apart. As she ages very quickly, her life expectancy is only 13 years old.

"Her skin gets tighter and tighter and her joints become arthritic. Most of the youngsters die because of heart attacks just like in old age."

Since that dreadful moment almost three years ago, the family has not only learned to cope, but to enjoy life. Instead of joining a special school, she attended the local playgroup, Sidley Starters.

In September, she is due to begin at Sidley County Primary School, with the cameras following her every step of the way. The school has gone to extraordinary lengths to ensure her life will be ordinary.

Kerry said: "We have just had a meeting with the head. We are obviously concerned as Hayley could suffer from a heart attack at any moment but we were told the school would make sure at least two teachers would be trained to deal with it.

"They would also contact the local ambulance service and hospital to make sure that everyone is alert in case of an emergency.

"Doors have also been loosened in the school so Hayley can open them as she isn't very strong. If she has to have a wheelchair in later years, they will adjust the doors to accommodate her.

"Basically, someone will always keep an eye on her. All the pupils know who she is anyway and they always try to mother her.

"The only trouble we're having is trying to find a school uniform. She only weighs about 22Ib and is 90cm high, so getting one so small is proving difficult."

As the condition is so rare, there are no drugs to control it. Even scientists in America are light years away from fully understanding why people get the disease. All they know is that it is a mutant gene.

But there is one ray of hope in the worldwide support group The Sunshine Foundation, based in America.

Mark said: "We have been to America for the last three years. We go every summer, although this year only Hayley and I could go.

"There are about 32 children who spend nearly a week together at a hotel. There is total freedom. All the kids look the same and the parents have been through the same thing.

"Everyone loses their inhibitions. It is the perfect time to relax. The cameramen filmed her packing her suitcases and when she was out there. It was really great fun."

Hayley is a shining example to other sick children. She also has a new brother, Louis, who was born in June.

Kerry said: "We just want people to be aware of the situation and if the TV documentary helps, then that is great. We are not getting anything out of it personally.

"It may sound clichd but we just take one day at a time. I can't imagine the day that Hayley is not with us. She could have a heart attack any day, so we just appreciate every minute she is on this Earth."

Mark is trying to raise money for The Sunshine Fund. To make a donation, go to Hayley's web site, www.hayleysprogeriapage.com