Researchers at Columbia University used genome-editing technology to modify DNA in human embryos with unprecedented accuracy. The breakthrough could pave the way for the birth of children with selected traits.
The new technique allowed scientists to replace single genetic letters in DNA sequences without causing the collateral damage often seen with CRISPR, an earlier form of gene editing.
In the experiment, they modified genes linked to cholesterol levels and haemoglobin production, the researchers said.
However, the scientists noted that the study left many questions about harmful side effects unanswered, and it is too early to consider clinical use of the method.
Study leader Dieter Egli stressed that the prospect of editing DNA in human embryos has sparked intense debate for more than a decade, since the invention of CRISPR.
On the one hand, Egli said, the technology might one day allow parents to safely correct disease-causing mutations in embryos. But it could also be used to select desirable traits.
In April 2026, U.S. scientists moved closer to treating Down syndrome using gene editing.
