In a Risky First, Scientists Edit Human Embryos' DNA
Experiment in China has limited success, raises host of ethical issues
By John Johnson,  Newser Staff
Posted Apr 23, 2015 5:28 PM CDT
File photo of a nonviable embryo.   (AP Photo/Richard Drew)

(Newser) – Advances in DNA research are fairly common these days, but a new study out of China seems to qualify for bombshell status: Scientists there edited the genes of human embryos for the first time, reports Nature. This gets into controversial and "ethically charged" territory, notes the MIT Technology Review, because if a mistake is made at the embryonic level, the mutation could get passed on to future generations. It also raises a whole new set of concerns about "designer babies." To dampen the controversy, the researchers out of Sun Yat-sen University did not use embryos capable of developing into babies. As they explain in Protein & Cell, they used a new gene-editing technique called CRISPR/Cas9 on 86 embryos to try to modify a gene responsible for a blood disorder. Things did not go well.

"Only 28 had the defective sequence removed, and an even tinier fraction of those ended up with the 'pasted-in' healthy genetic sequence," reports Quartz. Worse, mutations were introduced elsewhere. Researchers stopped the experiment, calling the technique "too immature." Critics not only agree, they want a moratorium on all such work. "There needs to be careful consideration not only of the safety but also of the social and ethical implications of applying this technology to alter our germ lines," a Harvard researcher tells NPR. At National Geographic, Carl Zimmer compares the controversy to the early days of human cloning and suspects "this week will go down as a pivotal moment in the history of medicine." This particular experiment may have tanked, but it's not a "deal-breaker" for the technology, he writes. But, as with cloning, society may now have to make some decisions about what's appropriate. (Read more about why some scientists want to halt gene editing in humans.)