The CRISPR enzyme (green and red) binds to a stretch of double-stranded DNA (purple and red), preparing to snip out the faulty part. Illustration courtesy of Jennifer Doudna/UC Berkeley hide caption

itoggle caption Illustration courtesy of Jennifer Doudna/UC Berkeley

Vera Wojtesta was one of 300 babies flagged by New York's newborn screening program as at risk of having life-threatening Krabbe disease. Ben Shutts/Courtesy of the Wojtesta family hide caption

itoggle caption Ben Shutts/Courtesy of the Wojtesta family

Slides containing DNA sit in a bay waiting to be analyzed by a genome sequencing machine. David Paul Morris/Bloomberg via Getty Images hide caption

itoggle caption David Paul Morris/Bloomberg via Getty Images