“Some 24 weeks after surgery, in February this year, tests in Cambridge showed Opal could also hear soft sounds such as a whisper.”
Opal Sandy was born completely deaf from a fault in the OTOF gene. One infusion of a working copy into her right ear gave her responses at 25 to 30 decibels, against roughly 20 for normal hearing. The headline says cured. The trial has three children on a low dose in one ear, and the drug belongs to Regeneron.