What is the name of the baby boy who became the first gene-edited baby, treated with a custom in vivo CRISPR treatment for a rare genetic disease in 2025?

In a groundbreaking medical advancement of 2025, a baby boy named KJ Muldoon became the first individual to receive a custom in vivo CRISPR gene-editing treatment for a rare genetic disease. Born with severe carbamoyl phosphate synthetase 1 (CPS1) deficiency, a life-threatening urea cycle disorder, KJ's case marked a historic milestone in personalized medicine. This innovative therapy was developed and administered by a collaborative team from the Children's Hospital of Philadelphia (CHOP) and Penn Medicine, with contributions from the Innovative Genomics Institute (IGI) at the University of California, Berkeley.

CPS1 deficiency is an ultra-rare condition that prevents the body from properly breaking down proteins, leading to a dangerous buildup of toxic ammonia in the blood, with a 50 percent mortality rate in infancy. Prior to this personalized CRISPR treatment, the only effective long-term solution was often a liver transplant. The specialized therapy for KJ involved using CRISPR, a revolutionary gene-editing technology often referred to as "molecular scissors," to precisely correct the specific genetic mutation in his liver cells that caused the disorder.

The success of KJ Muldoon's treatment, which involved multiple infusions and has shown promising results with the infant thriving and tolerating increased protein intake, signifies a new era for genetic medicine. This personalized, on-demand approach to gene editing, developed within a remarkably short timeframe, paves the way for potential future therapies for other rare and previously untreatable genetic diseases. It demonstrates the growing capability of CRISPR to make precise changes directly within a patient's body, offering hope for countless individuals facing similar debilitating conditions.