Sisters from Watford will be making the extra day count this leap year, by taking to the skies for a 10,000ft skydive and raising funds for vital research into devastating muscle-wasting diseases.

Sharon Kelly’s son Spencer, 19, was diagnosed with the life-shortening muscle-wasting condition Duchenne muscular dystrophy in 1992 at just four years old.

Sharon, 48, and younger sister Julie McNicol, 46, are taking on the challenge to help support research into treatment for the condition.

On February 29 the pair, along with friends Donna Byrnes and Jackie Kimpton, will face their fears and take the plunge in support of the Muscular Dystrophy Campaign’s Make Today Count campaign.

The charity is appealing to the public to use the extra day in 2012 to raise £30,000 for research into treatments and cures for muscular dystrophy and other neuromuscular conditions.

Sharon said: “I’m really petrified about the jump, but I’m determined to go ahead with it, it’s something I’ve always wanted to do and it’s for such a great cause.

"Two years ago I took part in a Great Wall of China Trek for the charity which was a fantastic experience but this year my sister and I wanted to do something together to help my son and other children and adults living with these conditions.

“We have a real chance to find the first treatment for muscular dystrophy and I hope people in Watford will back us on February 29 and raise funds so that we can continue promising research.”

The Muscular Dystrophy Campaign is looking for a further 100 daring recruits to join Sharon by taking on a sky-dive challenge in recognition of the 100 children born in the UK with Duchenne muscular dystrophy.

Aspiring daredevils wishing to take part will be asked to raise £400 sponsorship for their efforts and can choose from a variety of sky-dive sites.

Those without a head for heights can get involved with a host of other fundraising activities taking place on the day.

Muscular dystrophy and other neuromuscular conditions cause muscles to weaken and waste over time, leading to disability and in the case of some types of the disease, significantly shortening life-expectancy.

The Muscular Dystrophy Campaign has been funding research into treatments and cures for the conditions for more than 50 years, and has helped pioneer specialist care for the 70,000 people of all ages across the UK who are affected.