"It is possible that the key to immortality is hidden in this delicate girl, who is only about two feet, six inches tall and weighs 15.4 pounds. Her arms and legs are as fragile as the branches of a young tree. ... She has no hormonal problems, and her chromosomes seem normal. But her development is proceeding 'extremely slowly,' says Richard Walker, a geneticist with the University of South Florida College of Medicine. If scientists can figure out what is causing the disorder, it might be possible to unlock the mysteries of aging itself. 'Then we've got the golden ring,' says Walker."