Gene therapy shows promise in treating glycogen-storage disease

GAINESVILLE, FLA. — Veterinarians and physicians from the University of Florida's Glycogen-Storage Disease Program believe they have successfully used gene therapy to treat a dog born with glycogen-storage disease.

The dog has survived 20 months and is still healthy after receiving gene therapy.

Glycogen-storage disease prevents the body from using stored sugar. Dogs that suffer from the disease must be fed sugar every 30 minutes to survive.

"Without treatment, these dogs all die," says Dr. David Weinstein, director of the program.

Glycogen-storage disease Type 1A stems from a faulty enzyme that doesn't convert glycogen to glucose.

The goal of gene therapy is to restore the faulty enzyme so the body uses sugar properly.

The dog used in the study received its first dose of gene therapy the day after it was born. It improved at first, often going as long as two to three hours without needing additional glucose to supplement its diet. But several weeks later the progress stopped.

When the dog was 5 months old, researchers administered another dose of gene therapy. Six weeks after the therapy, the dog was completely weaned off glucose supplements.

The longest a dog with the disease had lived prior to the study was 28 days.

Researchers hope to establish a clinical trial in humans, but for now want to test gene therapy in dogs again within the next year.

UF's glycogen-storage disease program is the largest in the world.

Veterinary collaborators include John Verstegen, Travis Cossette, Sean Germain Karine Onclin-Verstegen and Andrew Specht, of the UF College of Veterinary Medicine and Maggie Struck and Harvey Ramirez, of UF Animal Care Services.