First Patient Treated with CRISPR Gene Therapy Released from Hospital

KJ Muldoon, a 10-month-old baby diagnosed with a rare and deadly genetic disorder called carbamoyl-phosphate synthetase 1 (CPS1) deficiency, has been released from the Children’s Hospital of Philadelphia after receiving the world’s first personalized CRISPR gene-editing therapy. This condition, which affects about 1 in 1.3 million people and has a 50% infant mortality rate, causes toxic ammonia buildup in the body. KJ’s doctors developed a bespoke gene-editing treatment that was first infused at seven months old, leading to remarkable improvements including healthy weight gain and milestone progress. His discharge was celebrated with a “clap out” by hospital staff and an escort home by local law enforcement, marking a historic milestone in translating CRISPR technology from research to real-world medical application. KJ’s parents expressed hope and joy at his homecoming, calling the treatment a miracle and looking forward to his continued development. This breakthrough highlights advancing gene-editing therapies for ultra-rare diseases and offers new possibilities for patients previously facing fatal prognoses.