Get in, drive off, get out: Taxis reliably take us from one place to another. In the future, medicine will also make use of this capability. In this case, however, it is not people who are being transported, but genetic information that could one day be used to treat genetically caused hearing loss, such as otoferlin-related deafness.
Hearing loss from birth
Otoferlin syndrome is classified as a “rare disease.” Worldwide, only about 200,000 people are affected by this genetic disorder. They are born with severely impaired hearing in both ears or even complete hearing loss.
This hearing loss is caused by a defect in the OTOF gene. This gene is responsible for ensuring that the sensory cells—which transmit auditory stimuli to the brain in the form of electrical signals—function properly. If this protein is missing, no auditory signals reach the brain, and the child is born deaf.
Genetic hearing loss accounts for up to 80 percent of all cases of deafness or severe hearing loss in children and newborns before they begin to acquire language. The OTOF genetic defect is responsible for one to eight percent of hereditary hearing loss. According to estimates by the University Clinic for Ear, Nose, and Throat Medicine in Tübingen, 15 to 25 children are born in Germany each year with this specific form of genetic hearing loss.
Clinical Gene Therapy Trial Offers Hope for Hearing
Until now, children with genetic hearing loss have often received cochlear implants, which stimulate the auditory nerve via an electrode inserted into the cochlea. Research into gene therapies for hearing loss is now opening up initial opportunities on the path to new treatment options. The idea: to deliver the missing gene directly to the inner ear and correct the defect. Prof. Dr. Ellen Reisinger and her team at the University Hospital of Tübingen demonstrated as early as 2019 that this method is effective in mice.
How a Gene Taxi Works
To deliver the correct version of the OTOF gene into the body, the researchers use a harmless virus as a carrier. They use a syringe to inject this “gene taxi” through a small opening in the bone, directly to where it belongs: the cochlea. Once there, it releases the correct genetic information that was previously missing or defective. The repaired gene can ensure that the hair cells once again produce the necessary protein and convert sound into electrical signals that the brain can process as auditory stimuli. The effect of the treatment is expected to last at least in the long term, and ideally even for life.
Initial results from past, international, independent studies are promising: Children treated with the Gene Taxi were able to respond to sounds or music about six months later. Some were already able to understand simple words or their own names and even began to speak on their own.
In Germany, the University Hospital of Tübingen was the first hospital to test this novel treatment for genetic hearing loss—specifically, otoferlin-related deafness—in April 2025. Doctors are now hoping for similarly positive results.
That's why good hearing is so important, even in childhood
Hearing is more than just perceiving sounds: it is the foundation for language development, social bonding, and education. Children who hear poorly or not at all have difficulty learning to speak. To ensure that language develops appropriately for their age, hearing impairments should ideally be addressed during the first year of life.
One example of this is the newborn hearing screening performed in the first few days of life: Within a few minutes, a pediatrician painlessly examines newborns by measuring so-called otoacoustic emissions—active acoustic emissions from the inner ear—to determine whether the newborn’s inner ear is functioning properly.
A Useful Complement to Cochlear Implants and Hearing Aids
In connection with its research, the University Hospital of Tübingen explicitly emphasizes that the new gene therapy does not compete with cochlear implants. Cochlear implants have so far been an effective solution for improving the quality of life for those affected. They can also be used to treat other forms of hearing loss in children and adults and will continue to be one of the best possible treatments for severe hearing loss bordering on deafness. Cochlear implants remain particularly suitable for hearing loss in children who, for various reasons, are not eligible for the clinical gene therapy trial.
For now, the “gene taxi” only works for a small group of people affected by genetically caused hearing loss. This is because there are over 150 different genetic causes of inner-ear deafness. Only a small fraction, such as Otoferlin-related hearing loss, has been studied or is even amenable to treatment. Researchers worldwide are working to further develop the method. The hope is that, in the future, other forms of genetic inner-ear hearing loss will also be treatable with similar gene therapies.
A Breakthrough in Audiology
Even though it may still be many years before the gene taxi can be widely used, the research is already encouraging. It shows that novel gene therapies have the potential to specifically treat genetically caused hearing loss and thus fundamentally transform the field of hearing medicine. For the language development and social participation of children with hearing loss or deafness, this innovation represents a major breakthrough.
Gene therapies for hearing loss could serve as a useful complement to hearing aids and cochlear implants. Regardless of which solution those affected and their families choose, it is important to identify the underlying cause of hearing loss in children and adults and to provide them with the best possible care. Read here to learn how untreated hearing loss can affect quality of life as well as physical and mental health.
