Marc Buchet
6 Mar 2024
A team of scientists at the Children’s Hospital of Philadelphia (CHOP) was able to treat the child with the first-ever gene therapy for genetic hearing loss in the U.S.
Gene therapy for hearing loss is something that we physicians and scientists in the world of hearing loss have been working toward for over 20 years, and it is finally here,” said John A. Germiller, Associate Professor at Perelman School of Medicine at the University of Pennsylvania, in a press release.
The 11-year-old, who was born deaf and was living in a poor community in Morocco until last year when he moved to Spain with his family, was eligible for the study because his hearing loss was caused by OTOF mutations. This accounts for 2% to 8% of cases of congenital deafness, according to a Reuters report.
An eleven-year-old born with otoferlin gene (OTOF)-mediated hearing loss was the first patient to receive this gene therapy in the study. On October 4, 2023, the patient underwent a surgical procedure at CHOP where the gene therapy was placed into the inner ear using a device called an endoscope that allows the ear drum to be partially lifted, allowing an investigational medical device to be transiently inserted into the “round window,” a tiny entry point into the cochlea. A single, small dose of a gene therapy (AK-OTOF) containing copies of the normal OTOF gene was then delivered directly to the inner ear. This delivery method represents the first time a gene therapy has been used as a potential treatment for hereditary hearing loss in the United States.
The patient was born profoundly deaf in both ears. Now, almost four months since receiving the investigational gene therapy in one ear, the patient’s hearing has improved enough that he now has only mild to moderate hearing loss in the ear that was treated. The patient is literally hearing sound for the first time in his life. He can hear his father’s voice, the sound of a car passing by and even the scissors clipping his hair.
While hearing loss can be caused by a variety of factors, like illness, injury, aging, exposure to loud noises or malformations of the inner ear, it can also be caused by a variety of genetic mutations. To date, more than 150 different genes have been implicated in hearing loss, and about 1 in 500 newborns are affected by some form of genetic hearing loss.
To learn more about this clinical trial, visit the study.
One in 500 newborns is affected by genetic hearing loss globally.
One in every 500 newborns has congenital or prelingual hearing loss with a severity that will affect language development.
In at least 50%, a genetic etiology can eventually be identified. Roughly 25% can be attributed to acquired etiologies like infections, and still a large portion remains of unknown origin. Hereditary hearing impairment (HHI) can be classified in different ways based on the identified locus of the gene defect, inheritance pattern, age of onset, audiological, and clinical phenotype.