Hayley Okines, the teenager who brought awareness to the world regarding a rare genetic disease that leads to premature aging, has passed away. She was 17 years old.

Okines from Bexhill, England was able to survive four years longer than the predictions of doctors after she was diagnosed as a baby with the Hutchinson-Gilford syndrome, a genetic disorder that is more popularly known as progeria.

She passed away - now with her body estimated to be 104 years old - after a short fight against pneumonia, BBC News reported. The teenager's death was confirmed through the Progeria Research Foundation.

"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," posted the Progeria Research Foundation on its Facebook page. "'Gone from our sight, but never our memories, gone from our touch but never our hearts...' We will miss you."

Progeria Research Foundation executive director Audrey Gordon said that Okines helped in educating millions of people regarding the rare disorder.

According to Gordon, Okines was a pioneer, being among the first people to participate in clinical drug trials and research that started the progress for developing treatment for progeria. Gordon added that Okines was one of the reasons why there is now the first cure for progeria.

"It took tremendous courage and determination by Hayley, her family and others like them to bring us to this point of progress, and we join her family and millions of people around the world in mourning her passing," said Gordon.

Okines helped spread word about progeria through online posts and co-writing a couple of books, Old Before My Time and Young at Heart, focusing on growing up with the disease.

Progeria is a very rare genetic disorder that affects only one person out of every 4 million to 8 million people. Worldwide, about 250 children have progeria, which causes the children to prematurely age at a rate that is around eight to 10 times faster than children without it. Other symptoms of progeria include stunted growth, baldness and the loss of body fat.

Children affected with the disorder go through symptoms of old age early, such as osteoporosis, arthritis and cardiovascular disease. According to the Progeria Research Foundation, the affected children only live to be about 14 years old.