Gene Therapy and Childhood Hearing Loss: What Parents Need to Know

Thanks to the latest scientific advancements and innovation, the field of hearing healthcare continuously evolves. Lately, there has been a lot of conversation about genetic therapies to treat hearing loss in infants and young children. This is big news for hearing healthcare and the future of hearing loss! 

What is Gene Therapy and Why Should Parents Be Aware of it?

While the findings reported in these studies show great scientific progress, it’s not clear what this can mean for YOU as a parent of a child with hearing loss today. You may be wondering: Is your child eligible? Does gene therapy cure childhood deafness? 

Because this information on genetic therapies is so new, we all have more questions than answers on what these scientific breakthroughs mean for children with hearing loss today. The recent news about genetic therapy and the otoferlin gene has sparked questions for parents of children with hearing loss and the professionals who serve them. Let's dive into the study and explore what it means for the future of hearing loss!

What do the studies show? 

In early 2024, two medical journal articles talked about two different genetic therapy studies conducted in China. The studies included children with a unique type of deafness caused by a mutation in a gene called the otoferlin gene. 

Many of the children in these studies had a considerable improvement in their hearing after receiving genetic therapy. In some cases, these children went from being completely deaf to being able to hear in the mild hearing loss range. Also, some of these children were able to show improvement in their ability to respond to speech. 

A report in The New York Times talked about a similar otoferlin genetic therapy study happening in the United States, under the watch of the FDA.   

So, what is an otoferlin mutation?

Before we answer that, let’s understand how the ear works. Sound travels down the ear canal and is captured by the eardrum, which sits at the end of the ear canal. The sound causes the eardrum to vibrate. Those vibrations are carried to the inner ear or the cochlea. Inside the cochlea, tiny receptors called hair cells change the vibrations into signals that go to the brain through the hearing nerve. 

An otoferlin mutation disrupts the gene that creates a protein that’s necessary for the hair cells to send the audio message to the hearing nerve. Without this protein, the audio message cannot go from the hair cells to the hearing nerve. In most cases, this results in profound deafness caused by a specific type of hearing loss known as an auditory neuropathy hearing disorder.

Otoferlin gene mutations are responsible for about 1-2%—or maybe even less— of genetic hearing losses present at birth. Many of these children receive cochlear implants and learn to listen and talk like kids with typical hearing.  

What is genetic therapy?

In short, with genetic therapy normal genes are transplanted into cells to replace the defective or missing ones. This can correct a genetic disorder, condition, or disease.

Genetic therapies can work in several ways. For example, a genetic therapy may: 

• Replace a disordered gene with a healthy copy 
• Stop a gene that is causing a disease
• Deliver a new gene into the body to help treat a disease

In the otoferlin gene therapy studies, a healthy copy of the otoferlin gene is put into a harmless virus, which is sent to the inner ear. The gene therapy also contains an agent called a promoter. The promoter is designed to deliver the healthy gene to the exact place in the inner ear that is affected. The introduction of the healthy gene is then able to correct for the mutated otoferlin gene and might bring back some hearing! 

What do these genetic therapy advancements mean for a baby with hearing loss?

This is a question many parents might have after hearing about the study. First, it's important to know that the genetic therapy studies so far only included kids with otoferlin mutations. Otoferlin mutations are just a small part of hearing problems present from birth, and there are over 150 genes causing hearing loss. This means it will take a while before there are genetic therapies for other types of childhood hearing loss.

The otoferlin gene change is easier to treat with genetic therapy compared to other genes causing hearing loss. So it might be many years or decades before genetic therapies are ready for other types of genetic hearing loss.

Even with otoferlin genetic therapy, the studies are still very early. There is still much more to learn before the FDA says it’s safe and effective. It will probably be at least several years before the FDA will approve the otoferlin genetic therapy as a clinical treatment.

What role does genetics play in MY child’s hearing healthcare? 

As research suggests, there is a critical window of time for kids to learn to listen and talk. A child needs access to sound by age three to five to develop strong listening, spoken language, and literacy skills. Given that genetic therapies will not be clinically available for many years at the earliest, parents can’t afford to wait if their baby is born with hearing loss today. 

The most important thing is to ensure your baby’s brain has immediate access to clear speech to develop the neural pathways and networks that allow them to develop listening and talking skills. Your pediatric audiologist and hearing healthcare team can help you determine if your baby needs hearing aids or cochlear implants. 

With modern hearing technology and pediatric hearing healthcare, children born with hearing loss today can learn to listen and talk just like other kids! If you help them use their hearing aids and cochlear implants during all waking hours and expose them to a language-rich listening environment, the sky is the limit!  

Hearing First has plenty of resources to support you as you teach your child to listen and talk. 

But genetics still plays an important role in your child’s care! Talk with your hearing healthcare team about getting genetic testing for your child if you don’t already know the cause of their hearing loss. In many cases, genetic testing can identify the cause, which helps your hearing healthcare team to provide the best possible care for your baby.

Want to take a deeper dive into understanding the role of genetics in hearing loss? Hearing First offers a self-study course, Genetics and Hearing Loss: Fundamentals of Genetics, for free that goes into more detail. Designed for hearing healthcare professionals, the course is open to parents and families interested in diving deeper into the role of genetics in hearing loss.

Learn More Here