Gene Editing Offers Hope for Stargardt Disease

Researchers have developed a groundbreaking gene editing therapy to treat Stargardt disease, the most common form of inherited macular degeneration that leads to progressive vision loss. Utilizing a precise technique called base editing, the therapy has demonstrated promising results in preclinical studies.

The findings, led by Professor Bence György and Professor Botond Roska from the Institute of Molecular and Clinical Ophthalmology Basel (IOB) and the University of Basel, were published in the journal Nature Medicine.

Understanding Stargardt Disease

Stargardt disease affects approximately 1 in 6,500 individuals and is classified as a rare disease. It primarily causes:

• Central vision loss: Making it difficult to recognize faces and read.

• Early onset: Symptoms often begin in childhood or before the age of 20.

Currently, there are no effective treatments for Stargardt disease.

Revolutionary Gene Editing Approach

The researchers employed base editing, a technique that enables the precise replacement of individual building blocks of DNA, known as nucleotide bases.

Key Features of the Therapy

• Targeting the Mutation: The therapy focuses on correcting the most common genetic mutation associated with Stargardt disease.

• Delivery System: Modified viral vectors deliver the editing system directly into retinal cells.

• High Success Rates:

• 75% correction in cone cells (critical for central vision).

• 87% correction in retinal pigment epithelial (RPE) cells, which support photoreceptors.

"Our approach achieves remarkably high rates of gene correction. These rates far exceed what we believe is necessary to provide clinical benefit to patients," said Professor György.

Tested on Human Tissue

The technique was tested on human retinal tissue, including retinas from organ donors, showcasing its potential for real-world application.

Safety and Precision

Alissa Muller, doctoral student at IOB and first author of the study, emphasized the therapy’s safety:

We conducted extensive off-target analyses and found no evidence of unintended edits in the retina or other parts of the body. This is critical for developing a safe and effective therapy."

Broader Applications in Retinal Diseases

The researchers highlighted that this base editing technology could be adapted to treat other inherited retinal diseases caused by similar mutations. This marks a significant advancement in the field of ocular gene therapy.

Next Steps

The team plans to conduct further safety studies and prepare for clinical trials to bring the therapy closer to patient use.

Transforming Outcomes for Stargardt and Beyond

If successful, this innovative approach could provide a transformative solution for thousands of individuals with Stargardt disease and potentially other inherited retinal disorders.

“This breakthrough represents a major step forward in our ability to correct genetic causes of vision loss and offers hope to patients who currently have no treatment options,” the researchers concluded.

Reference:

Gustavo Della-Flora Nunes et al, Incomplete remyelination via therapeutically enhanced oligodendrogenesis is sufficient to recover visual cortical function, Nature Communications (2025). DOI: 10.1038/s41467-025-56092-6