Scientists discover a hidden gene mutation that causes deafness—and a way to fix it

Scientists discovered that mutations in the CPD gene cause a rare inherited form of deafness by disrupting the production of nitric oxide, a crucial neurotransmitter for inner ear function. This disruption triggers oxidative stress that kills delicate sensory hair cells responsible for detecting sound. Researchers successfully tested two potential treatments—arginine supplements and sildenafil (Viagra)—that improved cell survival and reduced hearing loss symptoms in laboratory models.