Holly Clarke has finally received a call to New York for the pioneering medical treatment that could save her life.

The desperately ill five-year-old, who is battling Batten's Disease, is one of just two children in the world at the moderate stage of the illness to be approved to trial the new treatment in New York.

Batten's Disease leads to the progressive deterioration of the brain and nervous system and Holly has already lost her sight and speech and can no longer walk unaided.

There is no known cure but, after Holly was cleared to try the treatment earlier this year, scientists from Cornell University's Weill Medical College in New York have set a date for the operation that could halt the disease.

Holly's mum, Shirelle, 35, of Derwent Road, said: "I felt relieved when I got the call. We have been waiting a long time but it was also a bit of a shock it will be so soon.

"I am still a bit nervous. It's like a roller coaster - feeling sick and happy and excited at the same time.

"I haven't been able to sleep properly for days. It's a really big operation but this could save Holly's life.

"We don't know unless we try, so we have to try. We don't have any alternative and we are lucky there is this option."

Holly will fly to New York with her parents for the treatment on August 9. She is due to spend two weeks in New York when she will undergo two days of brain scans, followed by an MRI scan, before eight hours of brain surgery which will involve her being unconscious for two days.

The treatment, through the American-based Nathan's Foun-dation, involves an enzyme being fed into the healthy parts of her brain, which have not yet been affected.

Medics will drill six little holes into her skull and, over eight hours, the enzyme will be slowly injected. After that Holly will be taken into intensive care and will have another MRI scan after 48 hours.

Her father Darren, 34, said: "We are chuffed to bits - absolutely delighted. The nerves have settled and I am really excited.

"I told Holly and her little eyebrows kept raising up, which is what she does when she understands us."

Holly and one of her parents are being flown to the United States courtesy of Virgin Atlantic after tycoon Richard Branson heard about Holly's plight from cabin crew who had met the little girl.

She will have to return to New York twice after two 30-day periods and, if the operation works, she will be monitored for the next 15 years.

Well-wishers have raised more than £30,000 to pay for specialised equipment and treatment for Holly since she was diagnosed with Batten's Disease just over a year ago.