In a groundbreaking case of personalized medicine, researchers rapidly developed a gene-editing therapy to treat a newborn with a rare and deadly liver disorder—carbamoyl-phosphate synthetase 1 (CPS1) deficiency. Using CRISPR base-editing tools, the team created a bespoke therapy in just six months after diagnosis. The therapy helped stabilize the infant’s health, allowing increased protein intake and reducing medication needs—even through viral illnesses that previously posed life-threatening risks.

What made this fast-track treatment possible? Mice. Specifically, gene-edited house mice played a critical role in validating the therapy before it reached the patient. Researchers engineered mice to carry the same human genetic mutation, enabling them to test both the safety and efficacy of the customized treatment. Without this preclinical mouse model, such a rapid and precise intervention would have been far riskier and less likely to receive regulatory approval.

Notably, one of the study’s authors is also a center director for the Mutant Mouse Resource & Research Centers (MMRRC), highlighting the vital connection between mouse model infrastructure and clinical innovation. This case not only shows how deeply intertwined mouse genetics are with human health breakthroughs but sets a new bar for how personalized medicine can move from bench to bedside—fast.

Paper: https://www.nejm.org/doi/full/10.1056/NEJMoa2504747