Doctors rewrite DNA of infant with severe genetic disorder

Embargoed until: Publicly released: 2025-05-16 11:48

International

Penn Medicine’s Kiran Musunuru and Rebecca Ahrens-Nicklas holding KJ post infusion. Credit: Children's Hospital of Philadelphia

In a medical 'first', US doctors have used gene editing techniques to rewrite the DNA of a baby boy, known only as KJ, who was born with severe CPS1 deficiency, a rare genetic disorder that results in a buildup of toxic ammonia in the body. The team first identified the specific genetic mutations affecting KJ, and then designed a gene-editing therapy to correct them. The therapy is based on a procedure called base editing, which allows scientists to rewrite DNA one 'letter' at a time. KJ received the first dose of treatment in February this year, followed by doses in March and April. The team says KJ is now thriving, although he will need careful monitoring throughout life.

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Journal/
conference: New England Journal of Medicine

Research:Paper

Organisation/s: Children’s Hospital of Philadelphia, USA, University of Pennsylvania, USA

Funder: Supported by grants from the National Institutes of Health (U01TR005355 and U19NS132301, to Drs. Musunuru and Ahrens-Nicklas; R35HL145203, to Dr. Musunuru; U19NS132303, to Dr. Urnov; and DP2CA281401 and P01HL142494, to Dr. Kleinstiver). In-kind contributions were made by Acuitas Therapeutics, Integrated DNA Technologies, Aldevron, and Danaher. Additional funding was provided by the Children’s Hospital of Philadelphia Research Institute’s Gene Therapy for Inherited Metabolic Disorders Frontier Program.

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