In February last year, Doherty - now about age 65 - began to experience the same early breathing symptoms his father had had. As an avid hiker who has trekked the Himalayas, he was surprised to find himself getting winded on local hill walks. Testing confirmed that Doherty had a hereditary form of ATTR amyloidosis.
But there was one bit of good news: If Doherty had been diagnosed even a year earlier, no treatment options would have been available to him - an all-too-common situation for over 30 million U.S. patients with rare diseases. But Gillmore, Doherty's doctor, offered him the chance to participate in an early stage clinical trial using CRISPR, a groundbreaking genome editing therapy with the potential to cure his ATTR amyloidosis in a single dose.