auditory neuropathy-optic atrophy syndrome

Auditory neuropathy-optic atrophy syndrome is a very rare inherited condition in which changes in the FDXR gene damage the mitochondria, the parts of the cell that make energy, leading to problems with the nerves for hearing and vision. Most people begin to notice gradual hearing loss and blurred vision during childhood or the teen years. The severity and specific features can vary considerably from person to person; some lose hearing first, others notice vision changes earlier, and the speed of progression is different for each individual. The syndrome affects fewer than one in a million people worldwide and has been found in both boys and girls. Early diagnosis helps families seek hearing aids, vision support, and genetic counseling.

The hallmark features are optic atrophy and auditory neuropathy, meaning that the optic nerve and the auditory nerve progressively lose function. Children or adolescents typically notice difficulty hearing soft sounds, trouble understanding speech in noisy environments, or a need for higher volume on electronic devices. At a similar age, they may develop blurred or narrowed vision and problems with color discrimination as optic atrophy advances. Over time, visual impairment can progress to significant vision loss. Not all individuals experience all features, and severity varies considerably. Less common findings include rhythmic eye movements (nystagmus) and rod-cone dystrophy, which can add night blindness or peripheral vision loss to the clinical picture.

Auditory neuropathy-optic atrophy syndrome is inherited in an autosomal recessive pattern. This means an individual must receive two altered copies of the FDXR gene—one from each parent—to develop symptoms. FDXR produces ferredoxin reductase, an enzyme that supports mitochondrial electron transport; loss of its function appears to impair energy supply to the highly active optic and auditory nerves. Because two carriers are required for a child to be affected, the condition is more common when parents share a common ancestor, increasing the chance that both carry the same rare genetic variant. When both parents are carriers, each pregnancy has a 25 percent chance of resulting in an affected child, a 50 percent chance of a carrier child, and a 25 percent chance of an unaffected non-carrier. Genetic counseling can help families understand testing options and reproductive choices.

Currently, management focuses on supportive care and symptom management tailored to the individual’s hearing and visual needs. Hearing rehabilitation may involve hearing aids, frequency-modulated (FM) systems, or cochlear implantation when appropriate. Vision support can include low-vision services, orientation and mobility training, and assistive technologies such as screen readers or magnification devices. Because both hearing and vision can change over time, regular surveillance by audiology and ophthalmology specialists is recommended to detect progression early and adjust interventions. A multidisciplinary team—often including audiologists, ophthalmologists, neurologists, low-vision therapists, educators, and genetic counselors—helps coordinate care, address educational accommodations, and monitor overall well-being. Patients should discuss emerging therapeutic approaches and clinical trial opportunities with their healthcare team as research advances.

Outcomes described in medical literature continue to evolve as standards of care improve. At present, most children with auditory neuropathy-optic atrophy syndrome can expect stable overall health, yet the speed of hearing and vision loss differs from person to person. Some keep useful hearing or sight well into adulthood, while others need hearing aids, cochlear implants, or visual aids during childhood or the teen years. Regular visits with audiology and eye specialists, early speech therapy, and low-vision training can help protect daily skills and independence. Families are encouraged to meet with a genetic counselor to discuss test results, future planning, and family risks, and to seek peer support groups for shared advice and emotional support.