A new gene therapy treatment gained FDA approval last month to treat boys ages four and five with Duchenne muscular dystrophy, a rare and deadly genetic disorder that leads to muscle degeneration.

Connor Stoll from Chicago was the first patient in the nation to receive the infusion as part of a clinical trial at Nationwide Children’s Hospital in January 2018.

“He's doing amazing. Boys his age, typically, with Duchenne are on their way to being wheelchair bound,” said Kathryn Edison, Connor’s mother.

Connor’s parents first noticed he was struggling with movement in preschool.

“He had a hard time getting up off the ground. He was not keeping up with his peers on the playground. We noticed he had difficulties climbing stairs and just he had a very big waddle to his gait,” Edison said.

The eventual diagnosis of Duchenne muscular dystrophy was shocking.

“It's nothing that you ever want your child to be diagnosed with,” Edison said.

Found mostly in boys, the genetic disorder leads to progressive muscle degeneration, including the heart muscle.

“They are in wheelchairs by their early teenage years and the heart muscle is then affected and that really leads to their demise,” said Dr. Jerry Mendell, Director of the Center for Gene Therapy at The Research Institute of Nationwide Children’s Hospital in Columbus, Ohio.

Connor’s family traveled to Columbus to meet with Dr. Mendell in 2017, just as he was starting a clinical trial for gene therapy treatment.

Through the use of a disabled virus, the intravenous treatment delivers a replacement gene for the one that is mutated.

“We put in the gene that makes the muscles work and then we make millions of copies of that with the gene in place inside the virus and we inject it into their vein. It takes about an hour and a half. Gene therapy is a one-time treatment,” Mendell said.

In January 2018, Connor Stoll became the first patient in the country to get the gene therapy infusion. Now five and a half years later, Connor is still mobile, able to run and jump and play with his younger brother, Keegan.

“The gene therapy child definitely gave him his childhood back,” Edison said. “If you look at him, you can't really tell that he has Duchenne. He is able to run around and play sports with his friends and he loves swimming and playing baseball and he loves doing all the things that 11 year old boys do.”

The treatment received FDA approval in June to treat boys ages four and five with Duchenne muscular dystrophy.

“It’s the most gratifying experience that I personally have ever had to see the life changes of these boys,” Mendell said.

There are concerns about availability though, as the treatment comes with a $3 million price tag.

“You look at how well this medicine has helped Connor and other boys who have been in the trial and to see insurances not wanting to approve the medicine as a therapy and how expensive it is just to even get dosed. It's, it is jaw dropping,” Edison said.

While the treatment may not help all families with a loved one diagnosed with DMD, Connor’s family believes it’s a reason for hope.

“This is really historic and it's life changing and it's really going to change the trajectory of this disease,” Edison said.