On Thursday, April 2, it was announced that 17-year-old progeria victim Hayley Okines had passed away in East Sussex, England.
The condition called; Hutchinson Gilford Progeria Syndrome, also known as HGPS or Progeria, causes children with it age up to 10 times faster than normal.
Hayley's mother, Kerry Okines, posted the news on Facebook: "My baby girl has gone somewhere better. She took her last breath in my arms at 9.39 pm."
Hayley - who BBC News say had the "body of a 104-year-old" - was being treated in the hospital for pneumonia, but she returned home shortly before she died. "She came home for an hour and she saw her puppies, little brother Louie and her sister Ruby," Hayley's father, Mark Okines, told BBC News on Friday, April 3.
He added; "I think she wanted to come home to say goodbye to everybody," he continued. "I think she knew that yesterday was going to be the time."
Children with progeria rarely live past the age of 14, often passing away from ailments that affect the elderly, such as heart disease and stroke.
Hayley was told she would not live past the age of 13, but in 2007, the teenager began undergoing pioneering treatment at Boston Children's Hospital, US, as part of the first clinical trial for the condition.
In September 2012, the trial was a success.
In a statement following Hayley's death, the Progeria Research Foundation (PRF) praised the teenager for her contribution to progeria research:
"The entire PRF community mourns the loss of one of our shining stars, Hayley Okines. Hayley was one of the first participants in the ongoing progeria clinical trials. Hayley was a pioneer - and one of the reasons that we now have the first treatment for progeria. Today we remember her tremendous courage and determination," the statement said.
Hayley was an avid campaigner for progeria awareness, hailed locally and nationally as an inspiration for people with and without the condition. The teenager wrote two books detailing her experiences of living with progeria - "Old Before My Time" and "Young at Heart" - and took part in numerous interviews.
The news of Hayley's death comes just 15 months after it was announced Sam Burns, a boy from Massachusetts, United States had died from progeria. He was 17 years old too.
Progeria is caused by an abnormal protein in the LMNA gene, called progerin, which interferes with the production of lamin A - a protein that stabilizes a cell's nucleus.