BEST-SELLING Oxford author Mark Haddon has written a television drama about Down's syndrome.

Mr Haddon shot to fame four years ago with The Curious Incident of the Dog in the Night-time, a novel about a teenager with Asperger's syndrome.

Now he has written a drama for BBC1, thought to be the first British film or television production where the lead actor has Down's.

Tommy Jessop will play the role of Ben in Coming Down the Mountain, which tells the story of the tensions caused in a family when they move home to be nearer the 17-year-old's special school.

Mr Haddon, from East Oxford, whose novel sold about 10m copies, worked with young people with learning and physical disabilities before becoming a full-time writer. He said it was important disabled people became more accepted on screen.

He added: "People with disabilities get a raw deal in drama. There are few parts for them and those few parts usually involve being wheeled on and off screen so the 'normal' characters can emote interestingly about them. They rarely get to steer the plot. I wanted to redress that imbalance."

Coming Down the Mountain centres on Ben and his 15-year-old brother David, who is angry the family must leave London for Derbyshire.

The drama eventually takes the two teenagers to Snowdonia, where David plans to push Ben off a peak.

Down's, a genetic disorder, affects about 60,000 people in Britain. Symptoms include learning disabilities and physical problems. The Down's Syndrome Association helped with casting, writing to 600 parents whose youngsters had the disorder.

After the first week's filming, Tommy said: "I love playing the starring role."