In a lab room, a toddler, deaf from birth, sits while a tone plays. There’s no reaction. His face does not change. Six weeks later, after a single injection of an experimental gene therapy, the same toddler is back in the same room. The tone plays. The toddler’s head turns toward the sound. And somewhere just off screen, the child’s grandfather says his name. The boy turns and looks. He can hear. Good News A weekly dose of stories chronicling progress around the world. “When the parents realized their child had a response to sound they cried,” says Dr. Yilai Shu of the Eye & ENT Hospital of Fudan University, who co-led the trial, in a video that showed the results . “The whole family cried.” The video cuts to another child, thirteen weeks post-treatment, dancing to music. This is what gene therapy can do in 2026.…