He ate, played and learned like any other kid. But David Vetter's life unfolded in a series of unusual environments: plastic, bubblelike enclosures that protected him from germs. He had severe combined immunodeficiency (SCID), and even a seemingly harmless germ could kill him.
The subject of pop culture scrutiny and medical fascination, David was called "the boy in the bubble" by the media. SCID is rare and often fatal; it affects about 1 in 58,000 infants.
The disorder is created by genetic mutations that cause patients to produce too few of the immune cells that protect the body from infection. In healthy immune systems, T and B cells - known as lymphocytes - attack foreign organisms. People with SCID lack these critical immune defenses.
David, who lived in Texas, wasn't supposed to grow up in isolation. But while doctors waited for a cure, they decided to keep him in a sterile environment.
Raising a child in plastic isolation was developmentally risky and ethically questionable. But exposing David to the outside world meant death. Doctors thought a cure was just around the corner. Meanwhile, David became a long-term research subject.
Precocious, bright and sociable, he challenged expectations at every turn. (He did have visual problems that stemmed from being raised entirely in enclosed spaces, and he exhibited symptoms of depression.)
During his long confinement, medical technology progressed. But an experimental bone marrow transplant from his sister was David's death sentence. Undetected Epstein-Barr virus in her marrow triggered lymphoma. He died of the cancer in 1984 at age 12.
Because he was brought up in a sterile environment, his death allowed researchers to confirm a long-standing hypothesis that Epstein-Barr can cause cancer.
David's short life also provided insights into how SCID works. Better bone marrow screening now means more transplants are successful. According to the Immune Deficiency Foundation, 91 per cent of infants who are diagnosed early and given transplants by age 3 1/2 months survive.
Today, David's medical records and personal papers are held by the Smithsonian Institution. Perhaps the most touching of the museum's artifacts are his "Star Wars" action figures - a painful reminder of the child at the centre of a medical drama he could not control.