CNN reports that "A one-time snip of a key gene lowered heart-clogging cholesterol by about 50% over an entire year with no adverse effects, scientists have reported."The overwhelmingly positive results were found in four people who had taken the highest dose of the experimental treatment during a pilot study published in The New England Journal of Medicine in November 2025. That study was extremely small — only 15 patients with dangerously high cholesterol that did not respond to medication. The research was designed to test the safety of five different doses of a gene-altering infusion delivered by CRISPR-Cas9, a biological scissor which cuts a targeted genetic location to modify or turn a gene on or off. "If you'd asked me 15 years ago if we could have done something like this, I would have thought you were crazy," senior study author Dr. Steven Nissen, chief academic officer of the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic in Ohio, told CNN previously. An update on the study, published Friday in NEJM, appears to answer a key question: Does the intervention last? "Is something like this truly a one and done? That was always the question," said lead study author Dr. Luke Laffin, a preventive cardiologist at Cleveland Clinic's Heart, Vascular & Thoracic Institute. "This new data is essentially saying that the decreases in LDL cholesterol and triglycerides we saw at 60 days after treatment have lasted over a year," Laffin said. "In people who took the highest dose, the reduction seems durable and safe...." If larger clinical trials show similar results, the procedure could be a game changer for young people with severe disease, preventive cardiologist Dr. Ann Marie Navar, an associate professor of cardiology at UT Southwestern Medical Center in Dallas, told CNN previously. "If you're 20 and you have really high cholesterol, it may make a lot more sense to have a one-time treatment that doesn't require you to have to take a pill every single day or shot every two weeks for the next 60 years," said Navar, who was not involved in the study. "The potential for this is just enormous." Being born with this mutation naturally "drastically lowers or even eliminates a person's risk for heart disease," the article points out. And the study's senior author adds "now that CRISPR is here, we have the ability to change other people's genes so they too can have this protection."Read more of this story at Slashdot.