Gen therapy for hearing impairment
After a rocky start, gene therapy is now making progress. Researchers want to use them to treat a specific form of deafness.
The young woman tensely observes the facial expressions and gestures of her counterpart and nods or smiles when she thinks it might be appropriate. Because although the volume of her hearing aid was only recently increased, she hardly understands anything in conversations. Hannah Corderman suffers from a congenital condition called Usher Syndrome, which slowly but surely robs her of two main senses. Due to a genetic mutation, cells in your inner ear and retina no longer produce sufficient amounts of certain proteins that are required for normal cell function. Therefore, in addition to the loss of hearing, her eyesight has also deteriorated. Even as a teenager, she had to refrain from driving at night. Now in her mid-20s, blind spots make it difficult for her to see, even during the day. Doctors diagnosed her with Usher syndrome type 2A, an inherited hearing and visual impairment that gradually develops over the years. Currently, no therapy can stop or at least slow down the progression of the disease. So the young woman lives with the knowledge that in 10 years - maybe even 20 if the disease develops slowly - she will be deaf and blind.
There isn't much the doctors can do to help her. They could one day put Corderman in a cochlear implant that stimulates the auditory nerve directly, effectively bypassing the hair cells in the inner ear. This would still enable a certain sound perception even if the best hearing aids are no longer sufficient for this. The loss of function of the retina, in turn, could be counteracted with retina implants, which electrically stimulate the light-sensitive cells. But they are rarely used because they don't really come close to the actual visual sensation.
Though Corderman is not an avid reader of scientific journals, she knows that several hundred mice with a hearing impairment similar to hers are kept in a few Boston labs not far from where she lives. But unlike her, the rodents are doing better and better …