Click Here to Play Audio

Karson Blanchard has lived with Duchenne muscular dystrophy for most of his life.

It’s a degenerative disease that causes children who have it to lose the ability to walk by their teenage years. Without early intervention, their life expectancy is about 25.

On Wednesday, he received a new treatment that may help him live longer.

The FDA approved a new gene therapy drug, Elevidys, in June for four and five-year-olds who can still walk on their own. Karson turns six on Friday.

CHKD director of neurology and neuromuscular medicine, Crystal Proud, is Karson’s doctor. She said Karson’s care team scrambled to get the one-time injection ready by his birthday. The FDA cutoff is taken seriously — once Karson turns six, he’s no longer eligible.

“It became a race against time,” Proud said.

Duchenne muscular dystrophy almost always affects males. Their bodies don’t produce dystrophin — a protein that keeps muscles strong. Elevidys helps bodies produce dystrophin. Clinical trials, Proud said, resulted in boys with the injection able to ride bikes far longer than their peers who weren't treated.

“He is the first to receive a commercial dose of Elevidys in the state of Virginia and one of the first in the country. It's a great birthday gift,” Proud said.

Karson’s parents, Katy and Chris Blanchard, want to make sure they get as many birthdays as possible with their son.

Katy Blanchard said she’d heard whispers about gene therapy when Karson was first diagnosed at age 2.

“That was always sort of what kept me going … the hope that something would come out,” she said.

“And now it has. And we're lucky enough to be in the small population of people that can receive it. So, you know, I feel like our hope’s coming to life.”

She said her son’s attitude has made it easier for their family to live a normal life.

“I think it's his personality. He's a bubbly, easygoing, larger than life kind of kid. He's happy 95% of the time,” she said.

Karson said he’s excited to get “special medicine.” But now he’s focused on more important things — like Cheez-Its, chocolate milk and "Paw Patrol."