Sport-loving Mark Smith is looking forward to the trip of a lifetime canoeing the mighty Yukon River in Canada.

The 17-year-old has suffered from a rare brain condition since the age of four which affects his speech.

But he will be part of a high-powered team of young people to attempt the expedition next summer, camping in the wilderness, retracing the path of the gold prospectors, and avoiding wild bears.

Now he is appealing to local businesses to give sponsorship to help him raise his fundraising target of £2,300.

"Mark is really looking forward to it," said his mother Wendy, who works with disabled children. "He has never been on an aeroplane before and he is really looking forward to seeing the wild animals like elk and bears."

Mark's father Allan, who is a crane driver, added: "We think this trip will give him extra independence, away from us - it will be the first time he has been away for more than a weekend."

The teenager is a pupil at Chapel Grange Special School and won the chance of the trip thanks to expedition organiser Alan Elsworth, who teaches there. The trip is being organised under the banner of the Yorkshire Schools Exploring Society.

Mr Elsworth said: "Mark is the only pupil with special needs on this trip, the other ten people will come from all over Yorkshire. He's turned out to be a grand lad.

"It's a fantastic trip. It retraces the steps of the old gold prospectors. We fly to Vancouver, take the ferry up the Alaskan sounds and see Great Whales, and then canoe 370 miles in three and a half weeks down the Yukon river. We will be camping on the river bank every night - we will be in the wilderness for over three weeks. We will be trying to avoid bears by hanging bells around our waistbands and putting food in bags and hanging them in trees."

Mark is one of a handful of people in the UK who have Launda-Kleffner Syndrome, a rare form of epilepsy which affects the part of the brain dealing with language. When he was younger experts thought he was deaf, although his hearing later proved to be normal. He is keen on sports and plays rugby league for Victoria Rangers.

"He is getting slightly better and comes out with new words all the time," said his mother Wendy.

Anyone who can help Mark's sponsorship target is asked to call Chapel Grange School on (01274) 773307.