Editing Human Embryos

[phkrause]

Scientists have edited the DNA of early human embryos with a new level of precision for the first time, using an upgraded gene-editing technology that avoids the unintended damage seen in earlier versions. The development suggests it may one day be possible to correct disease-causing mutations before birth. 

The work, led by scientists from Columbia University, was conducted on lab-grown embryos intended for research, not for implantation. It builds on CRISPR-Cas9, a tool that works like molecular scissors, snipping DNA at targeted locations to remove or replace faulty genes (visualize how it works). A newer approach—base editing—allows scientists to swap individual DNA letters without fully cutting the strand. The refinement can reduce mutations that occur during DNA repair and could open the door to treating diseases caused by single-letter genetic errors, such as sickle cell.

The breakthrough heightens concerns about using the gene-editing technology to enhance traits. In 2019, a Chinese scientist was sentenced to prison for secretly editing embryos to make them HIV-resistant in the first known case of gene-edited babies (w/audio).