hello there.: When you are born old : Meet the teenager trapped in the body of a 100-year-old.

Hayley Okines, who suffered a rare genetic condition that gave her the body of a 100-year-old has died aged 17

A teenager suffering a rare genetic condition that gave her the body of a 100-year-old has died aged 17.

Hayley Okines hit the headlines three years ago when she was part of a documentary about her premature ageing condition.

She suffered from the rare disease progeria which ages the body at eight times the normal rate.

Progeria takes its name from the Greek word 'proeros', meaning prematurely old.

It involves a mutant protein called progerin that accelerates physical ageing.

There are around 74 known cases of the disease around the world and only 4 in the UK.

A 10 year old progeria child will have the appearance of an octogenarian with symptoms including baldness, arthritis and heart problems, but the mind of a 10 year old.

Progeria patients normally die from heart attacks or strokes at an average age of 13.

But Hayley, from Bexhill, East Sussex, defied the odds to live four more years and even published an autobiography about living with the disease.

Last night her mother Kerry posted on Facebook: 'My baby girl has gone somewhere better. She took her last breath in my arms at 9.39pm x.'

Today, the Progeria Research Foundation posted on its Facebook page: 'The entire Progeria family mourns together with many as we say goodbye to Hayley Okines, our smart, beautiful and spirited English rose, who passed away today at age 17.

'Gone from our sight, but never our memories, gone from our touch but never our hearts. We will miss you.'

Hayley and her family had fundraised for her medical treatment and to raise public understanding of the condition.

Her story was catapulted into the limelight after she starred in documentaries called The Girl who is Older than Her Mother and World's Oldest Teenager: Extraordinary People.

Her autobiography, called Old Before my Time, detailed pop-star crushes and a dislike of school.

But it was also a moving insight into how a child copes with a disease which resulted in Hayley having the body of a 105-year-old.

In an interview with The Sunday People in 2013, her mother described the hell of living with the disease.

'The most difficult part is Hayley has the mind of a normal 13-year-old girl locked in an old person's body,' she said.

Last night her mother Kerry posted on Facebook: 'My baby girl has gone somewhere better. She took her last breath in my arms at 9.39pm x.'

'Someone else has to get her a drink as she's too small to reach taps by herself.

'And buying fashionable clothes is tough because she still wears clothes for a five-year-old.

Hayley, who turned 17 on December 3, left school last summer.

However, despite pioneering drug treatment in the US that gave her a new lease of life, she was unable to conquer the disease.

In recent weeks her health had deteriorated and she contracted pneumonia.

After being discharged yesterday she died at home last night.

Hayley's parents have previously described the heartache her condition had caused.

Her mother said: '[When she was born] she had fine blonde hair, blue eyes and her father and I were besotted with her.

'At 10 months she walked for the first time – we were so proud.

'The only concern was she was so petite and didn't appear to be growing.

'But as I'm only 5ft 4ins I tried to tell myself she simply took after me.'

At 13 months, Hayley still wore clothes for a three-month-old, so her mother took her to their GP.

Tests revealed she had a rare gene mutation called Hutchinson-Gilford progeria.

Her mother said: 'We looked it up on the internet and were shocked. We found photos of children who looked like little elderly people.

'They had bald heads and one girl was wearing a wig which made her look so odd it frightened us.

'It said sufferers wouldn't reach puberty and would eventually die from age-related disorders, usually before their teens.'

Next came the devastating news that Hayley would only live until the age of 13.

Determined to make the most of the time she had, the family embarked on giving Hayley amazing memories.

Members of the local community raised thousands of pounds to pay for her to go to Disneyland in California.

In her short life, Hayley went swimming with dolphins, travelled all over the world, met Prince Charles, Kylie Minogue and Justin Bieber and been in several TV documentaries.

Despite her terrible prognosis, the teenager remained upbeat. 'In many ways I feel I've been lucky. Because of this I've met more people and done more than many do in a lifetime,' she said.

Hayley even published an autobiography about living with the disease, called Old Before My Time.

Hayley and her family had fundraised for her medical treatment and to raise public understanding of the condition.