New Trick in DNA Editing Could Unlock Thousands of Cures

Narrower change+Lower Risk... 

A CRISPR startup rewrites tiny mutations instead of cutting and pasting entire genes.

For all its promise to cure disease, the gene-editing tool known as CRISPR still has a lot of unknowns. A big one is its safety: will it edit only the places in the genome it’s supposed to?

Perhaps the most contentious claim about CRISPR, that it could cause hundreds of unintended edits throughout a genome, has since been retracted. Even so, scientists still worry it could cause some unwanted DNA insertions or deletions. Other recent research indicates that some versions of CRISPR could make edited cells more vulnerable to cancer.

Such problems could be avoided with a more precise technique being developed in the labs of David Liu, a professor at Harvard and the Broad Institute. His team’s version of CRISPR involves so-called base editors, which go after much smaller targets — individual letters of DNA.