Patient-Specific In Vivo Gene Editing to Treat a Rare Genetic Disease

N Engl J Med. 2025 Jun 12;392(22):2235-2243. doi: 10.1056/NEJMoa2504747. Epub 2025 May 15.

Abstract

Base editors can correct disease-causing genetic variants. After a neonate had received a diagnosis of severe carbamoyl-phosphate synthetase 1 deficiency, a disease with an estimated 50% mortality in early infancy, we immediately began to develop a customized lipid nanoparticle-delivered base-editing therapy. After regulatory approval had been obtained for the therapy, the patient received two infusions at approximately 7 and 8 months of age. In the 7 weeks after the initial infusion, the patient was able to receive an increased amount of dietary protein and a reduced dose of a nitrogen-scavenger medication to half the starting dose, without unacceptable adverse events and despite viral illnesses. No serious adverse events occurred. Longer follow-up is warranted to assess safety and efficacy. (Funded by the National Institutes of Health and others.).

Publication types

  • Case Reports

MeSH terms

  • Ammonia / blood
  • Carbamoyl-Phosphate Synthase (Ammonia) / deficiency
  • Carbamoyl-Phosphate Synthase (Ammonia) / genetics
  • Carbamoyl-Phosphate Synthase I Deficiency Disease* / complications
  • Carbamoyl-Phosphate Synthase I Deficiency Disease* / diagnosis
  • Carbamoyl-Phosphate Synthase I Deficiency Disease* / genetics
  • Carbamoyl-Phosphate Synthase I Deficiency Disease* / therapy
  • Gene Editing* / methods
  • Genetic Therapy* / adverse effects
  • Genetic Therapy* / methods
  • Hepatocytes / enzymology
  • Humans
  • Hyperammonemia* / blood
  • Hyperammonemia* / diagnosis
  • Hyperammonemia* / genetics
  • Hyperammonemia* / prevention & control
  • Infant
  • Infant, Newborn
  • Liposomes / administration & dosage
  • Male
  • Nanoparticles / administration & dosage
  • Rare Diseases* / complications
  • Rare Diseases* / diagnosis
  • Rare Diseases* / genetics
  • Rare Diseases* / therapy
  • Treatment Outcome

Substances

  • Carbamoyl-Phosphate Synthase (Ammonia)
  • Lipid Nanoparticles
  • Liposomes
  • CPS1 protein, human
  • Ammonia