DAVID Whyte spent a decade in the RAF as an engineer but is now facing his toughest physical challenge yet – climbing Africa’s highest peak, Mount Kilimanjaro.

Mr Whyte, 45, from Wantage, who was stationed in the US, Germany, the Falklands and Cyprus, is scaling the Tanzanian mountain to raise funds for the charity Unique, which supports families with rare chromosome disorders.

“I used to do a lot of these adventure scenarios,” he said. “It’s going to be a significant challenge.”

Mr Whyte, who works for British Telecom managing an engineering team, and his wife Sharon, 42, are friends with Samantha Bennett.

Her son Otis, who turns two in April, has a rare chromosome disorder that means he is unable to crawl and has developmental issues.

Mrs Bennett, 31, of Chilton, who has an older son Jago, three, said she did not discover that Otis had a rare chromosome disorder until last October.

“When Otis was diagnosed they weren’t able to tell us anything,” she said. “It was all a bit of a whirlwind, really. We weren’t sure what to do.”

So Mrs Bennett and her husband, Stefun, 30, turned to Unique, a support group for families with rare chromosome disorders.

Unique’s chief operating officer, Craig Mitchell, said rare genetic disorders affect about one in every 200 people in the UK.

“It’s genetic material that’s either missing, or added on to a person’s chromosomes, or it can be rearranged,” he said. The condition could lead to “a whole range of learning and physical difficulties”, from mild to severe.

“The individual disorders are rare, but collectively they are much more common,” he said.

Due to the rarity of specific disorders, doctors often could not give parents guidance about their child’s future development. Some people carry a chromosome disorder without displaying any affects but may pass the gene on to a child who is significantly affected. Advances in blood tests have enabled more accurate screening.

Mrs Bennett said she and her husband were not carriers of a rare chromosome disorder.

Unique has 4,500 family members, including 46 in Oxfordshire, and has collated a database to try to give parents a sense of future developmental prospects for their children.

Mr Whyte will be part of a fundraising climb in March 2015 by travel agency group Not Just Travel, for which the Whytes own a franchise in Wantage.

Thirty per cent of funds raised will go to the Breast Cancer Awareness Campaign and 70 per cent to a charity of the franchisee’s choice.

Sharon Whyte, a mother of five who became friends with Mrs Bennett after meeting at a mothers’ group, thought of Unique when the climb was proposed.