A team of scientists from UT Southwestern Medical Center has successfully stopped the progression of Duchenne muscular dystrophy (DMD) in young mice using a new gene-editing technique. If the technique can be safely adapted for human use, it will mark the first successful genome editing treatment for the fatal disease, which is the most common and severe form of muscular dystrophy in young boys. The disease works by breaking down muscle fibers and replacing them with fibrous or fatty tissue, leading to a gradual weakening of the muscles and, in many cases, the stimulation of heart muscle disease.

"This is different from other therapeutic approaches, because it eliminates the cause of the disease," Eric Olson, senior author of the study, said in a press release.

The researchers used a CRISPR gene-editing technique that permanently corrected the DMD mutation that stimulates the disease in younger mice using the adeno-associated virus 9 (AAV9) to stimulate the production of dystrophin protein, which lead to improved skeletal muscle structure and function over time.

"AAV9 can efficiently infect humans in a tissue-specific manner, but it does not cause human disease or toxicity. It's a molecular missile for gene therapy," said Leonela Amoasii, co-lead author of the study with Chengzu Long.

"The CRISPR/Cas9 system is an adaptive immune system of single-celled organisms against invading virus," added Long. "Ironically, this system was hijacked, we packaged it into a nonpathogenic virus, and corrected a genetic mutation in an animal model."

The team is now working on applying the same gene-editing technique to human DMD patients and further testing its effectiveness in larger preclinical animal models.

"The recent groundbreaking discoveries from the Olson laboratory using genome editing to correct the genetic mutation that causes DMD have accelerated the race to find a cure for this deadly disease," said Pradeep Mammen, Co-Director of the UTSW Wellstone Center, which helped fund the research. "The challenge now lies before Wellstone Center researchers to translate these discoveries in the mouse model of DMD into a therapy for patients with DMD."

The study was published in the Dec. 31 issue of Science.