A team of physicians and laboratory scientists has taken a key step toward a cure for sickle cell disease, using CRISPR-Cas9 gene editing to fix the mutated gene responsible for the disease in stem cells from the blood of affected patients. For the first time, they have corrected the mutation in a proportion of stem cells that is high enough to produce a substantial benefit in sickle cell patients. The researchers from the University of California, Berkeley, UC San Francisco Benioff Children’s Hospital Oakland Research Institute (CHORI) and the University of Utah School of Medicine hope to re-infuse patients with the edited stem cells and alleviate symptoms of the disease, which primarily afflicts those of African descent and leads to anemia, painful blood blockages and early death. “We’re very excited about the promise of this technology,” said Jacob Corn, a senior author on the study and scientific director of the Innovative Genomics Initiative at UC Berkeley. “There is still a lot of work to be done before this approach might be used in the clinic, but we’re hopeful that it will pave the way for new kinds of treatment for patients with sickle cell disease.” In tests in mice, the genetically engineered stem cells stuck around for at least four months after transplantation, an important benchmark to ensure that any potential therapy would be lasting. ...