The N-of-1 accomplishment provides a template for swift, personalized genetic therapies.
News broke yesterday that researchers in Philadelphia appear to have successfully treated a 6-month-old baby boy, called KJ, with a personalized CRISPR gene-editing therapy. The treatment corrects an ultra-rare mutation in KJ that breaks a liver enzyme. That enzyme is required to convert ammonia, a byproduct of metabolism, to urea, a waste product released in urine. Without treatment, ammonia would build up to dangerous levels in KJ—and he would have a 50 percent chance of dying in infancy.