Scientists at Children's Hospital of Philadelphia, UC-Berkeley and Penn Medicine save newborn KJ with rare CPS1 deficiency using world's first custom in-vivo CRISPR gene therapy in February 2025; treatment developed in six months could help millions with genetic disorders.

Scientists Edited Genes Inside a Living Person for the First Time—and Saved His Life

Here’s what you’ll learn in this story.The world’s first bespoke gene therapy saved the life of a newborn with a rare genetic disorder that cause the build-up of life-threatening ammonia in the body. In a race against time, scientists and doctors across the U.S. developed the first in vivo gene therapy, thanks to decades of medical research. After three doses, the newborn patient showed drastic improvement, and this new era of in vivo gene therapies could save the lives of millions more in the f...