International Summit on Human Gene EditingFLICKR, NATIONAL ACADEMY OF SCIENCESCRISPR made The Scientist’s list of top advances two years ago, and again this year, thanks to seemingly weekly publications about new improvements to and uses of the gene-editing technology. The improvements reported this year include the use of CRISPR to edit the epigenome; a smaller Cas9 protein that fits in a viral vector for efficient in vivo genome engineering; the discovery of four new Cas proteins that could expand the gene-editing toolbox; and the engineering of an altered Cas9 that binds less tightly to mismatched DNA. But the biggest news this year was on the application side of the technology—namely, its use to edit the human germline.
In April, researchers at Sun Yat-sen University in Guangzhou, China, reported in Protein & Cell that they had successfully used the CRISPR/Cas9 system to cleave the endogenous β-globin gene in nonviable human zygotes. The study spurred a fury of debate over the proper use of CRISPR, and whether it’s ever OK to manipulate human embryos or gametes. “This study reaffirms the reasons that a pause is needed on in vivo human gene editing studies,” stem-cell researcher Paul Knoepfler of the University of California, Davis, wrote at his blog in April. Edward Lanphier, chairman of the Alliance for Regenerative Medicine, agreed. “In our view, genome editing in human embryos using current technologies could have unpredictable effects on future generations,” he and his colleagues wrote in a ...