David Vetter was born with an extremely rare genetic disorder known as severe combined immunodeficiency disease (SCID), where his immune system failed to develop normally. Immediately at birth in a hospital in Houston, Texas on 21 September 1971 he was placed in a protective cocoon and spent the rest of his 12 years of life the sterile environmental of a plastic bubble to protect him against infections that a healthy child would simply shrug off.
His surname was not revealed publicly until ten years after his death in 1984 and he became known as the “boy in the bubble” or “David, the bubble boy”. Everything that entered his sterile environment – food, water, clothing, toys – had to be treated in a chamber filled with ethylene dioxide for four hours at 60 Celsius.
David eventually received a bone marrow transplant from his sister Katherine, and although his body didn’t reject the transplant, he became ill with infectious mononucleosis after several months and died of Burkitt’s lymphoma. An autopsy revealed that Katherine’s transplanted bone marrow contained traces of a dormant virus, Epstein-Barr, which at that time was not detectable by pre-transplant screening. The virus was probably responsible for David's lymphoma.
It is now known that at least nine genes are known to be involved in SCID and that SCID children suffer a defect in one of several possible genes. The most common treatment for the condition is bone marrow transplantation from tissue-matched donors, ether relatives or non-relatives. Medical scientists have also attempted gene therapy with limited success. One of the problems is that the therapy involves the use of retroviruses to insert genetic material into the bone marrow of the child, which can cause leukaemia in later life.
Advances in gene-editing using the Crispr-Cas9 technology could, however, offer new hope to these children – who are born at a rate of about 1 in every 100,000 births.