July 28, 2017
Since Chinese researchers announced the first gene editing of a human embryo 2 years ago, many expected that similar work in the United States was inevitable. Last night, the MIT Technology Review broke the news that such experiments have happened. The research, led by embryologist Shoukhrat Mitalipov of Oregon Health and Science University in Portland, also reportedly sidestepped problems of incomplete and off-target editing that plagued previous attempts, though details could not be confirmed since the work is not yet published and Mitalipov has so far declined to comment.
If a peer-reviewed paper bears out the news story, “It’s one more step on the path to potential clinical application,” says bioethicist Jeffrey Kahn of Johns Hopkins University in Baltimore, Maryland, who served on a committee convened by the U.S. National Academy of Sciences (NAS) and the National Academy of Medicine in Washington, D.C., to address gene editing. The panel’s report earlier this year concluded that a clinical trial involving embryo editing would be ethically allowable under narrow circumstances.
The first published human embryo–editing work, in 2015, used nonviable embryos and targeted a gene mutated in the heritable blood disorder beta thalassemia. But it revealed major shortcomings in applying the increasingly popular CRISPR gene-editing technology. The few embryos that took up the change made by CRISPR were a patchwork of edited and unchanged cells, and they bore unintended edits outside the targeted gene.