Scientists have developed a CRISPR gene-editing technique that can potentially correct a majority of the 3,000 mutations that cause Duchenne muscular dystrophy (DMD) by making a single cut at strategic points along the patient’s DNA, according to a study from UT Southwestern Medical Center.

The method, successfully tested in heart muscle cells from patients, offers an efficient alternative to the daunting task of developing an individualized molecular treatment for each gene mutation that causes DMD. It also opens up possible new treatment approaches for other diseases that have thus far required more intrusive methods to correct single-gene mutations.

Scientists say the new strategy enhances the accuracy for surgical-like editing of the human genome, correcting mistakes in the DNA sequence that cause devastating diseases like DMD, a deadly condition caused by defects in the dystrophin gene. Normally, the dystrophin protein helps strengthen muscle fibers.

“This is a significant step,” said Dr. Eric Olson, director of UT Southwestern’s Hamon Center for Regenerative Science and Medicine. “We’re hopeful this technique will eventually alleviate pain and suffering, perhaps even save the lives, of DMD patients who have a wide range of mutations and, unfortunately, have had no other treatment options to eliminate the underlying cause of the disease.”

The research, the cover story of this month’s Science Advances, builds upon previous studies from Dr. Olson in which CRISPR-Cas9 corrected a single gene mutation that caused DMD in mice. The new study demonstrates how a wide range of mutations can be corrected in human cells by eliminating abnormal splice sites in the genomic DNA.

These splice sites instruct the genetic machinery to build abnormal dystrophin molecules, but once the gene is successfully edited it expresses a much-improved dystrophin protein product, enhancing the function of the muscle tissue.

“In fact, we found that correcting less than half of the cardiomyocytes (heart muscle cells) was enough to rescue cardiac function to near-normal levels in human-engineered heart tissue,” said Dr. Chengzu Long, lead author of the study and assistant professor of medicine at New York University Langone Health.