Can new gene therapy save children from 'bubble boy' disease?

New capabilities allow children chance to live without fear of isolation

LAKELAND, Fla. – Gene therapy treatment for a genetic condition doctors once considered one-in-a-million and treated using an isolation chamber known by most as "bubble boy disease" is showing promising results.

"Back in the '70s, we did put babies in bubbles," Heather Smith said from her living room in Central Florida.

It's almost impossible to start a conversation about Severe Combined Immunodeficiency, or SCID, without referencing the 1976 movie "The Boy in the Plastic Bubble," starring John Travolta. The film was inspired by the life of David Vetter, a child born in 1971 with SCID and treated in hospitals inside a specially designed sterile plastic bubble until he died at age 12.

"When you look down at your newborn baby and they look so perfectly healthy and you can't understand," Smith said.

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SCID affects the development and function of infection-fighting immune cells. Infants who are not screened for the condition are highly vulnerable to infections like pneumonia and can die within the first year or two of life.

Smith's first child, Brandon, was born with X-linked SCID in 1993, but like most other babies with the genetic mutation, did not show any signs of a compromised immune system until it was too late. He died at seven months.

"We feel like, he passed away so that Taylor could live," Smith said.

Doctors diagnosed her second son, Taylor, with SCID while Smith was pregnant, and he was the first patient in the world to receive an in-utero bone marrow transplant. The transplant allowed her second son to grow and develop his immune cells while inside the womb. After he was born, Taylor spent a few months in isolation, but later grew strong enough to attend kindergarten, run cross-country and graduate from college.

"He did great for 23 years," Smith said.

But because her son was the first child to be treated in-utero, doctors didn't know how long his immune system would stay healthy.

"There is no need anymore for bubbles, but there is still a place for isolation," Dr. Jennifer Leiding, director of the SCID Newborn Screening Program for the University of South Florida at Johns Hopkins All Children's Hospital, said.

In April, the New England Journal of Medicine announced that researchers at St. Jude Children's Research Hospital used a gene therapy treatment to cure infants born with SCID. The study followed eight infants with SCID for about 16 months. All were reported to be developing healthy immune systems after removing ineffective blood cells and using a virus to infuse a new gene back into the body.

"The only way to treat SCID is replacing the infant's immune system or fixing the infant's immune system," Leiding explained.

Until the recent breakthrough, doctors treated infants with SCID using a bone marrow transplant. The challenge was finding matching donors.

"Gene therapy is the new kid on the block, so to speak," Leiding said. "Instead of giving a new immune system to the infant, you are fixing their own immune system."

Smith's son, Taylor, has been on a waitlist at the National Institutes of Health to have the gene therapy, with the hope it will be a lifelong solution. Doctors with USF and Johns Hopkins All Children's Hospital said the results were promising, but would not call gene therapy a cure for SCID.

"The therapy hasn't been there long enough to know whether these therapies are going to be curative but they are definitely making a huge difference in the patient's life," Jolan Walter, the division chief of pediatric immunology at USF/Johns Hopkins All Children's Hospital, said. 

"In our eyes, if it was a cure then genetically it would stop and you wouldn't have to worry about the implications of it anymore," Smith said.

Because SCID is a hereditary disease, if Taylor has children, he could pass the mutation on to his daughters who would be carriers, like Smith.

Smith started a foundation for families to find resources for SCID. Click here for more information.