When little Harry Simmons was born he was desperately ill with failing kidneys.

The idea of the brave youngster competing against other children in sport was just a dream for his worried parents.

In February 2003, his father David was found to be a match and Harry, now three, underwent transplant surgery.

He has not looked back since and his parents are now helping him celebrate with an appearance at the British Transplant Games in Norfolk.

He will be in the ball-throwing competition, an obstacle course and a 50-metre dash.

Mum Karen Kingswood, from Southwater, near Horsham, said: "He is really looking forward to it and so are the rest of us.

"He is already a fast runner anyway but he's trying hard with the other events as well.

"The competition is fun but it is also a good chance for transplant patients young and old and their families to get together, socialise and share their experiences.

"Having someone in a family going through a transplant can be a hugely draining experience for everyone involved.

"Being able to talk to others who have been through the same thing really helps.

"The games also help raise awareness of the importance of organ donation and how it can save people's lives."

Harry's parents were told there was a problem as soon as he was born.

He was taken to the specialist Trevor Mann baby unit at the Royal Sussex County Hospital in Brighton and stayed in intensive care for three weeks.

Harry had developed a blockage in his urethral tube during Ms Kingswood's pregnancy which badly damaged his kidneys.

His lungs were also not inflated properly when he was born.

Ms Kingswood said: "They told us almost from the start his kidneys were bad and he was going to have to have a transplant at some stage. It was a difficult time but all our energies were focused on helping him."

Harry gradually began to build up his strength but was transferred to Guy's Hospital in London for more treatment when he was six months old.

He was given high protein food and fed through a tube as doctors worked on building him up so he would be strong enough for surgery.

Ms Kingswood said: "We managed to keep Harry going even through his kidneys were down to just five per cent effectiveness. Luckily, he did not have to go through dialysis."

Both parents were tested for their suitability to donate a kidney and both were a match. Insurance worker David, 32, decided to go through the operation.

Ms Kingswood, 34, said: "Either one of us could have done it but we decided that as I was the primary carer I should be the one to stay well throughout the whole thing.

"Both of them are now doing really well although I think Harry recovered faster than David did."

Shortly after surgery Harry met TV star Ulrika Jonsson, who was at Guy's Hospital to promote the work done by Ronald McDonald Houses.

The houses provide family rooms and a place to stay for parents whose children are in hospital.

He was at Guy's for about six weeks before being well enough to come home.

Harry has been doing well ever since and loves playing with his older sister Charlotte, 13, and brothers Ben, 11 and George, nine.

Ms Kingswood said: "He is a lively, typical little boy now. He goes to play-group and loves it. He's full of bounce and you always know when he's around.

"He may be one of the smaller children in the group but he's also the loudest. Nothing fazes him. He's cheeky and he makes you laugh."

The British Transplant Games were first held in 1978 with the aim of demonstrating the benefits of a successful organ transplant.

More than 50 teams from around the UK compete in the annual event, with ages ranging from two to 75.

Since April 1 this year 580 people have received transplants, leaving some 5,861 people in the UK still on the waiting list to receive a life-saving or life-improving transplant operation.

Fore more details about organ donation, go to www.uktransplant.org.uk or call the organ donor hotline on 0845 6060400.