Gegen eine Krankheit kämpfen, die junge Körper brutal altert

Progeria is a disease of rapid, brutal aging: by the time children afflicted with it enter their teen-age years, their bodies have effectively aged eight or nine decades. It arises from a spontaneous mutation present at birth, a C replaced by a T on chromosome 1; this produces an abnormal, toxic version of the protein called progerin, warping the cell’s nucleus. “The human genome contains billions of letters, enough to fill hundreds of books; the disease was apparently caused by the equivalent of a single typo,” Dhruv Khullar writes.

In a landmark 2016 paper, David R. Liu, a professor at Harvard and the Broad Institute who has built on CRISPR to develop novel gene-editing techniques, showed that a gene editor his lab had developed could home in on a specific genetic sequence, unravel the DNA, and change one base to another—a C to a T, say, or a G to an A. Starting in 2019, researchers incorporated Liu’s DNA editor into nonpathogenic viruses, injected them into two-week-old mice that had progeria, and found that about 30 per cent of cells in certain organs were successfully edited. The scientists observed a staggering 90-per-cent reduction in the toxic progerin protein in some tissues, possibly because edited cells replaced unedited cells over time. The hearts, livers, and blood vessels of treated mice appeared strikingly healthy. The data were so promising that they looked unreal, Liu told Khullar.

The mice that didn’t get the gene therapy died after about 200 days. Those that did lived more than 500—the rough equivalent of a human living to retirement age. “For the first time, it now seems plausible that progeria could be cured,” Khullar writes.