A 16-month-old girl named Ayla carried the genes for a rare genetic disorder. But doctors learned of it early and treated her for it — before she was born. Today she’s a thriving toddler. It was the first time such an early treatment had ever been given for this Pompe (Paam-PAY) disease.
The condition can damage organs of the body while a child is still developing inside its mother. By birth, affected babies have enlarged hearts and weak muscles. Without medical care, most will die before age 2. Treatment typically begins right after birth. But at that point, it’s too late to reverse any organ damage that took place in the womb.
Ayla was treated as part of an early-stage clinical trial. Today her heart works normally. She’s also meeting standard milestones for babies, including walking. Her progress suggests that getting treated before birth can prevent organ damage from this disease. That should greatly improve their lives of infants born with Pompe disease. Researchers described Ayla’s case last November 8 in the New England Journal of Medicine.
“It’s a great step forward,” says Bill Peranteau. He’s a pediatric and fetal surgeon in Pennsylvania at Children’s Hospital of Philadelphia. He did not take part in the work.
Enzyme replacement
Pompe disease affects fewer than 1 in every 138,000 babies. These children have genes that affect their ability to make an enzyme known as GAA. That stands for acid alpha-glucosidase (AL-fah-glu-KOS-ih-dayce). The body needs GAA. GAA breaks down glycogen, a complex sugar, into glucose. That glucose, a simple sugar, is the body’s main source of energy.
With Pompe disease, some children make only low levels of GAA. Others may make none at all. With too little GAA, glycogen may build up to levels that can damage muscles, including those in the heart and lungs.
Before Ayla was born, she was diagnosed with the most severe form of Pompe. Her body makes no GAA. So her organs were at high risk for life-threatening damage. Fortunately, Ayla qualified for a trial offering prenatal treatment.
Jennifer Cohen is leading the trial, which launched in 2020. Cohen is a pediatric geneticist at Duke University School of Medicine in Durham, N.C. The trial treats Pompe and seven similar conditions.
Ayla’s treatment began when her mother was 24 weeks pregnant. Researchers infused GAA into a vein of the umbilical cord. The medical team has continued infusions — now weekly — since Ayla was born. The girl will need to continue those treatments for the rest of her life.
Ayla and her mother had no ill effects, Cohen says. But it’s unclear whether this prenatal enzyme replacement will always be safe and effective. To know for sure, more patients will need to be treated and monitored in the trial.
This prenatal technique could be useful in treating other rare diseases, Peranteau says. But scientists must first show that any newly developed treatments (such as gene therapies) won’t have harmful long-term effects when given to babies after they are born.
Cohen and her team will continue to keep tabs on Ayla. “We’re cautiously optimistic, but we want to be careful,” she says. “Especially those first five years, I think, are going to be critical.”
