Science | November 11, 2017 5:00 am

How a Gene-Carrying Virus Is Saving Infants’ Lives

New gene therapy treatments could give children with rare diseases a second chance.

Evelyn Villarreal is one lucky three-year-old. Not only does she have extremely loving parents, but by most medical analyses, she shouldn’t be alive. According to a report in ScienceEvelyn has spinal muscular atrophy type 1 (SMA1), a genetic disease that gradually paralyzes babies. It killed her sister at 15 months. But when the Villarreals got pregnant again, they decided to have Evelyn, even though there is a one-in-four odds of a second tragedy.

But Milan Villarreal, Evelyn’s father, learned about a clinical trial in Ohio and sent an email to sign up his daughter. She’s since received a gene therapy treatment that gave her body a crucial, missing protein and Evelyn is now like a lot of three-year-olds, though she still has weak thighs.

The trial she participated in shocked researchers. All 15 babies treated for SMA1, who were expected to die by age 2, are alive at 20 months or older. Most can sit up, and one boy is also walking like Evelyn, reports Science. 

A drug that was recently approved for SMA1 has received similar results, but must be injected into the spine every four months. The gene therapy Evelyn received was a one-time treatment, infused through a vein.

The success of this gene treatment adds to the rising success of gene therapy overall. A treatment for a genetic form of blindness has not only been endorsed last month by a U.S. Food and Drug Administration advisory panel, but is also on track to be the first gene therapy in the U.S. approved for an inherited disease, Science reports

But the SMA1 study is different because it shows the power of a new vector, “a virus carrying a therapeutic gene that, infused into a vein, can carry its cargo to the central nervous system, across the so-call blood-brain barrier,” Science explains. Efforts to treat neurological diseases with gene therapy had previously been unsuccessful, but this SMA1 success has encouraged researchers to use gene therapy for rare childhood neurological and muscular diseases.

“It opens up a whole new concept to a field that has been very cautious,” Federico Mingozzi, the chief scientific officer of the gene therapy company Spark Therapeutics, told Science.