The technique used on a 9½-month-old boy with a rare condition has the potential to help people with thousands of other uncommon genetic diseases.

The work, they said, began decades ago with federal funding for basic research on bacterial immune systems. That led eventually, with more federal support, to the discovery of CRISPR. Federal investment in sequencing the human genome made it possible to identify KJ’s mutation. U.S. funding supported Dr. Liu’s lab and its editing discovery. A federal program to study gene editing supported Dr. Musunuru’s research. Going along in parallel was federally funded work that led to an understanding of KJ’s disease.