Baby Successfully Treated With First-Ever Personalized Gene Editing Therapy
The CRISPR technology had previously been used to target more common diseases.

Children's Hospital of Philadelphia
A nine-month-old baby has become the first person ever to be successfully treated with personalized gene editing therapy. Researchers corrected a specific gene mutation in baby KJ Muldoon‘s liver cells that had caused a rare metabolic disease called severe carbamoyl phosphate synthetase 1 (CPS1) deficiency, Penn Medicine announced. After spending his first several months of life admitted to the Children’s Hospital of Philadelphia (CHOP), KJ received the first dose of his bespoke therapy in February and is now growing well and thriving. Most CPS1 patients eventually need liver transplants, but before they’re old enough, the disease’s side effects can cause lifelong neurological damage or even death. KJ’s case marks the first time CRISPR gene editing technology has been used to successfully create a personalized cure, as opposed to being used to target more common health problems such as sickle cell disease. KJ’s treatment could “provide a pathway for gene editing technology to be successfully adapted to treat individuals with rare diseases for whom no medical treatments are available,” according to a statement from Penn Medicine. Dr. Rebecca Ahrens-Nicklas, one of the doctors who treated KJ, said she hopes the boy will be the “first of many” to benefit from personalized gene therapies. The breakthrough is the result of years of progress in gene editing and decades of federally funded research.

KJ with his parents Nicole and Kyle Muldoon.
Children's Hospital of Philadelphia
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