CRISPR DNA Editing Can Cause Hundreds of Off-Target Mutations

A new study offers a cautionary tale for using the widely hyped gene-editing tool CRISPR on people.

The gene-editing technology known as CRISPR has only been around for five years, but it’s already generated enough hype and controversy to last a lifetime. Compared to other gene-editing techniques, CRISPR is so fast, cheap, and precise that any scientist with a basic understanding of genetics can experiment with DNA — plant, animal, or human — by cutting out and replacing specific genes.

Some say that the ease and effectiveness of CRISPR will usher in a golden age of genetic modification resulting in new cures for inherited diseases like Huntington’s and muscular dystrophy and new gene therapies for eradicating cancer and HIV. Others see CRISPR as a Pandora’s box leading to a dystopian future of designer babies and expensive life-extending therapies that will further divide the world into genetic haves and have nots.

Now a new study complicates the CRISPR controversy by shining a light on CRISPR’s Achilles' heel — off-target mutations. CRISPR works by targeting short sequences of DNA base pairs in...