Perhaps the largest medical breakthrough this side of the Human Genome Project has been the invention of CRISPR, a technique for rewriting entire sections of DNA. CRISPR lets scientists target specific sections of DNA and edit them however they want, essentially giving scientists a potentially unlimited ability to fix genetic illnesses.
But there’s a catch: CRISPR might cause random side effects.
When scientists want to edit a gene with CRISPR, they use techniques to select a specific gene sequence to edit. But selecting a single region in an entire genome is not easy, and often CRISPR will target other regions in the genome as well. Researchers believed they could predict most of these “off-target effects,” but a new study in Nature Methods suggests they probably can’t.