CRISPR gene editing in human embryos wreaks chromosomal mayhem
By Heidi Ledford,
Nature
| 06. 25. 2020
Three studies showing large DNA deletions and reshuffling heighten safety concerns about heritable genome editing.
A suite of experiments that use the gene-editing tool CRISPR–Cas9 to modify human embryos have revealed how the process can make large, unwanted changes to the genome at or near the target site.
The studies were published this month on the preprint server bioRxiv, and have not yet been peer-reviewed1,2,3. But taken together, they give scientists a good look at what some say is an underappreciated risk of CRISPR–Cas9 editing. Previous experiments have revealed that the tool can make ‘off target’ gene mutations far from the target site, but the nearby changes identified in the latest studies can be missed by standard assessment methods.
“The on-target effects are more important and would be much more difficult to eliminate,” says Gaétan Burgio, a geneticist at the Australian National University in Canberra.
These safety concerns are likely to inform the ongoing debate over whether scientists should edit human embryos to prevent genetic diseases — a process that is controversial because it creates a permanent change to the genome that can be passed down for generations. “If...
Related Articles
GeneWatch UK has prepared a briefing on the genetic modification of nature for the International Union for Conservation of Nature (IUCN) Congress in October 2025
The upcoming Congress claims to be “where the world comes together to set priorities and drive conservation and sustainable development action.” A major concern for those on the outside is that the Congress may advance plans to develop and encourage the use of synthetic biology in nature conservation. This could at first glance sound like...
By Aaron Ginn, The Washington Post | 09.12.2025
Earlier this year, I had dinner in D.C. with Jensen Huang, the president and chief executive of Nvidia. At one point, he said something that struck me: “Why is everyone here so negative?”
He wasn’t referring to the economy...
By Roni Caryn Rabin, The New York Times | 08.25.2025
Scientists have dreamed for centuries about using animal organs to treat ailing humans. In recent years, those efforts have begun to bear fruit: Researchers have begun transplanting the hearts and kidneys of genetically modified pigs into patients, with varying degrees...
The Center for Genetics and Society is delighted to recommend the current edition of GMWatch Review – Number 589. UK-based GMWatch, a long-standing ally, was founded in 1998 by Jonathan Matthews as an independent organization seeking to counter the enormous corporate political power and propaganda of the GMO industry and its supporters. Matthews and Claire Robinson are its directors and managing editors.
CGS works to ensure that social justice, equity, human rights, and democratic governance are front...
