US Doctors Use Gene Editing to Treat Infant with Rare Genetic Disorder in World First

Doctors in the United States have successfully treated an infant with a rare genetic disorder using a customized gene-editing therapy, The Guardian reported. The baby, identified as KJ, was born with CPS1 deficiency, a condition that affects approximately 1 in 1.3 million people and can be fatal in infancy.

The treatment, developed by specialists at the Children’s Hospital of Philadelphia and the University of Pennsylvania, used a technique called base editing to correct the genetic mutation responsible for the disorder. The therapy was designed, manufactured, and tested within six months of KJ’s diagnosis. He received three infusions between February and April 2025.

Early results indicate that KJ is responding well to the treatment, though long-term monitoring will be necessary to assess its full effectiveness. The case was detailed in the New England Journal of Medicine and presented at the American Society of Gene and Cell Therapy annual meeting.

This breakthrough demonstrates the potential of gene-editing therapies to treat severe genetic disorders shortly after birth.