Penn Team Eyes CRISPR to Slow Muscular Dystrophy

Researchers in Philadelphia report a preclinical approach that boosts a stand-in protein, alongside a personalized gene-editing treatment for a rare infant disorder.

Updated on Nov. 3, 2026 in Biotech

Empty modern laboratory bench with a row of glass pipettes and a shallow dish of amber liquid, lit by soft daylight from a tall window. — Penn Medicine researchers reported a preclinical CRISPR approach that boosted the protein utrophin and improved muscle function in mice with Duchenne muscular dystrophy. AI Illustration. Upload story photo >

Penn Medicine researchers identified a new use for CRISPR gene editing to slow Duchenne muscular dystrophy in a preclinical model. Penn Medicine and the Children's Hospital of Philadelphia also treated an infant with a rare genetic mutation using personalized CRISPR gene editing.

Why it matters

Duchenne muscular dystrophy affects about one in 5,000 males and typically leads to death, so a treatment approach that improved muscle function in mice could matter for patients and families in the Philadelphia area. The infant case shows personalized gene editing being applied to a rare disorder, while Penn worked with the FDA on a new protocol for regulatory approval of rarer-disease treatments.

The evidence comes from a preclinical mouse study and a single-patient case, with Duchenne affecting one in 5,000 males and CPS1 deficiency affecting one in 1.3 million babies. Whether the utrophin approach works in humans, and how durable the infant's response will be, has not been established.

The players

Penn Medicine

The University of Pennsylvania's health system and research enterprise, which conducted the Duchenne research and worked on the infant treatment.

Children's Hospital of Philadelphia

A major pediatric hospital that partnered with Penn Medicine in treating the infant with CPS1 deficiency.

U.S. Food and Drug Administration

The federal agency that regulates drugs and gene therapies in the United States, with which Penn worked on a new protocol for rarer-disease treatments.

The details

Researchers boosted the protein utrophin to act as a stand-in for dystrophin, which Duchenne patients fail to produce in functional amounts, and the technique improved muscle function and microscopic tissue changes in mice. The approach combined two delivery systems already in use with CRISPR gene editing.

Last year: Penn Medicine and CHOP treated the infant with personalized CRISPR gene editing.

Big Picture

Penn's work on a new FDA protocol for rarer-disease treatments provides the regulatory pathway that the personalized CRISPR treatment for the infant with CPS1 deficiency appears to follow. The Duchenne mouse findings extend the same gene-editing research toward a much more common inherited muscle disease.

For families affected by rare inherited diseases, this research signals that personalized gene-editing treatments are moving from concept toward clinical use in the Philadelphia area. Readers should note that the mouse findings are preclinical and the infant case is a single patient, so no broadly available treatment has been established.

The takeaway

Personalized gene editing is advancing from single-patient cases toward a regulatory pathway for rare diseases, though the Duchenne approach remains at the preclinical stage. Patients and families should track peer-reviewed results before assuming any new treatment is available.