Scientists may have found a way of treating children with the rare genetic ageing disease progeria.

Eight-year-old Hayley Okines, from Bexhill, and two-year-old Ashanti White, from Burgess Hill, both suffer from the condition which means the ageing process is eight times faster than normal.

Until now there has been no hope for the 40 known cases around the world which result in dwarfism, baldness, wrinkles, hardened arteries and osteoporosis.

Most children with progeria die from heart disease before the age of 15.

There are four known cases in the UK, including Hayley, who featured in a Channel Five documentary called Extraordinary People last year.

In a study published in Science journal on Thursday, researchers at the University of California, Los Angeles, (UCLA) say they have found that an experimental cancer drug improves the signs of progeria in mice.

The majority of progeria mice showed improvements in body weight, bone integrity, grip strength and survival compared with untreated control mice. Dr Loren Fong, an assistant professor of medicine at the David Geffen School of Medicine at UCLA, told the journal: "This is the first study in an animal model to show such a drug could be useful in treating progeria and related conditions.

"We believe that these studies should give some hope to progeria patients and their families."

By the end of the 20-week study, six of 14 non-treated progeria mice had died compared with only one of 13 treated mice.

Dr Leslie Gordon, Progeria Research Foundation's medical director, said she was very encouraged by the first piece of evidence in an animal model.

She said: "This study gives us pieces of information critical to our movement toward clinical trials in children with progeria.

" This type of evidence will help us to ensure that children can safely take this drug."

Ashanti's grandmother Ann White, of London Road, Horney Common, near Nutley, said: "We heard about this from the Progeria Research Foundation.

"We hear so many different things that it's hard to know what to think. "It is good news but we have to wait and see what happens.

"We are always hoping something will happen but you don't want to get too excited just in case."

Hayley's mother Kerry Button said: "We are a bit excited about this news but also a bit apprehensive because we don't know what the side effects could be for Hayley. It's a lot of pressure because we don't know whether we should put her through something or not. It is a catch-22 situation.

"Time is everything to us, we don't know if Hayley will be with us next week or in ten years' time so we hope this will develop soon."

A form of progeria was the subject of a recent Channel Four documentary, The 80-year-old Children, which featured the only family in the world known to be struck by more than one case of the disease. Five children born to the Khan family in India have all been affected.