Doctors believe an eight-year-old US girl who has the body of a newborn baby could hold the secrets to biological immortality:
Montana girl Gabby Williams weighs just 5kg and still needs to be cared for like a baby.
"Gabrielle hasn't changed since pretty much forever," her mother Mary told US network ABC.
"She has gotten a little longer and we have jumped into putting her in size 3-6 month clothes instead of 0-3 months for the footies."
Gabby's condition is so rare that it does not even have a name.
Medical researcher Richard F Walker said Gabby has a slowed-down process of developmental inertia, the process that allows the body to grow and change as it ages.
"Without that process we never develop," he said.
"When we develop, all the pieces of our body come together and change and are coordinated. Otherwise, there would be chaos."
Dr Walker said the developmental inertia causes the internal order in the body to progressively erode as people get older.
Discovering the secret of Gabby's condition could lead to discovering a way to stop developmental inertia once people reach maturity.
"If we could identify the gene and then at young adulthood we could silence the expression of developmental inertia, find an off-switch, when you do that, there is perfect homeostasis and you are biologically immortal," Dr Walker said.
Humans would still fall victim to accidents and disease, but the causes of death that come with old age would no longer be an issue.
Author: Nick Pearson.