The reality is Benny and Josh both have Canavan disease, a fatal inherited brain disorder. They are buckled into wheelchairs, don’t speak, and can’t control their limbs.

On Thursday, April 8, in Dayton, Ohio, Landsman and his family rolled the older boy, Benny, into a hospital where over several hours, neurosurgeons drilled bore holes into his skull and injected trillions of viral particles carrying the correct version of a gene his body is missing.