From Bubble Boy to Normal Life: How Pioneering Gene Therapy Saved Rhys Evans

Rhys Evans Leaves the Bubble Behind After Pioneering Gene Therapy

A 26-year-old man who spent most of the first year of his life isolated inside a protective, filtered chamber after being born without an immune system is now working as stage crew at Butlin’s in Minehead, Somerset, following a landmark medical procedure performed 25 years ago. Rhys Evans received pioneering gene therapy at London’s Great Ormond Street Hospital in 2001 for X-linked severe combined immunodeficiency (XSCID).

• Rhys Evans was treated in 2001 at Great Ormond Street Hospital for XSCID, a rare inherited disorder preventing normal immune system development.
• The intervention involved extracting 100ml of bone marrow, inserting a functional copy of the faulty gene via a viral vector, and re-injecting the modified cells.
• More than 130 people have received the treatment since 2001.

The Burden of X-Linked Severe Combined Immunodeficiency

Before modern medical interventions, most infants born with severe combined immunodeficiency did not survive past their first birthday. The genetic condition leaves children at constant risk of life-threatening infections, chronic diarrhea, poor feeding, and severe respiratory illnesses like pneumonia. In the United Kingdom, Great Ormond Street Hospital estimates the condition affects approximately one in every 40,000 babies in England, translating to roughly 14 cases a year. Historically, the only available treatments were chemotherapy or a matching bone marrow transplant—options complicated by the severe weakness of the patients and, in Evans’ case, the absence of a matching donor.

The condition gained global attention through the case of David Vetter, a patient born in the US and nicknamed the “Bubble Boy,” who lived inside an isolation chamber and later a NASA-designed plastic suit until his death at age 12 following a failed bone marrow transplant. Evans faced a similar reality in his early months, living in a sterile room where visitors required sterilization and the air was strictly filtered to keep out viruses and bacteria.

Researchers Modify Bone Marrow Cells Using Viral Vector

The gene therapy administered to Evans was the culmination of 15 to 20 years of laboratory research led by Prof Adrian Thrasher at University College London alongside experts at Great Ormond Street. The procedure bypassed the need for a matched bone marrow donor by utilizing the patient’s own tissue. Clinicians extracted 100ml of bone marrow, introduced a correctly functioning version of the mutated gene into the immune cells using a viral vector, and reimplanted the marrow back into the patient’s body.

Prof Adrian Thrasher explained that the medical team simply waited for the modified bone marrow to regenerate the immune system naturally. Within weeks, Evans’ immune system began to develop. Shortly after turning two, he contracted the flu—a natural test of his new immunological capacity—which he successfully overcame. Thrasher noted that more than 130 people have received the treatment since 2001, and the team is moving on to tackle other similar disorders caused by a single gene defect.

Long-Term Health Outcomes and Current Status

Evans works as stage crew at Butlin’s in Minehead, Somerset. While he requires a weekly antibiotic infusion and manages warts on his hands, he has been able to attend school, go to university, and plan for a normal future. The gene therapy laboratory at Great Ormond Street Hospital was partly funded by the trust’s Jeans for Genes appeal, and clinicians are now looking to tackle other single-gene defects, including chronic granulomatous disorder.

Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.