BATON ROUGE - A newborn in Baton Rouge received a potentially life-saving drug just four days after she was born. Lexa Dennis is the youngest patient to ever receive Zolgensma, a $2.1 million dollar gene therapy drug that's said to stop spinal muscular atrophy in its tracks.

Charlotte Hollman, the pediatric neurologist who treated Lexa at Woman's Hospital says it was a group effort.

"This baby, through the hard work of Woman's Hospital and the doctors here, the nurses, the pharmacy people, the social workers... They worked very hard to get this baby the gene therapy treatment very quickly, including getting it approved by Medicaid," Hollman said.

Spinal Muscular Atrophy, or SMA, is a genetic disease that affects muscle movement and can cause death. Lexa's brother, Axel, also has SMA and was administered the gene therapy treatment in July last year, just two weeks before his second birthday. Right now, Zolgensma is only available to children 2 years old and younger.

The earlier the gene therapy is administered, the better. And in Lexa's case, she's the youngest baby to ever receive the one-time dose.

"The outlook for Lexa is possibly walking, breathing on her own, swallowing, all of the things that her brother - her hero -fought for her to be able to do," mom Andrea James said.

Doctors are optimistic about that too.

"Hopefully this will prevent her from having any symptoms of this horrible disease. Or if she does have any, they will just be mild," neonatologist Kimberly Stewart said.

James says she's already seen positive signs in her son and says her daughter has not been given the best chance she has.

"His quality of life is wonderful. He's a happy child. He brings joy to anybody he meets. And then Lexa, it's limitless," James said. "I think it's possible that she hits every milestone in what would be considered a normal kid."

The process was much different for James this time. She fought to get the treatment for her son for a year and was denied it twice. Before that, Axel was administered Spinraza every four months through spinal injection.

The gene therapy treatment Zolgensma has been available for about a year and a half. Before Lexa's treatment, the youngest baby administered Zolgensma was 10 days old.