DNA is more than just a blueprint; it’s part of the puzzle of who we are. It’s what gives us our unique features, from the sparkle in our eyes to the curve of our smile. Nestled within this complex framework, however, lies a subset of variations that dictate how our bodies function. These subtle genetic nuances can predispose us to various conditions, including hearing loss.
Genetics are thought to be responsible for 50% of all hearing loss cases. Genetic hearing loss, as it’s called, can arise from either non-syndromic or syndromic genetic mutations. Of these cases, roughly 30% are syndromic (associated with other medical conditions), while 70% are non-syndromic (meaning hearing loss occurs in isolation, without any other associated medical conditions).
Due to the high prevalence of genetic hearing loss in babies and adults, I work with a lot of patients who have questions about how genetic hearing loss happens — and how the cause of hearing loss impacts the treatment plan. So, let’s delve into an overview of the topic, covering treatment options, testing methods, and preventive measures specific to genetic hearing loss.
Genetic Hearing Loss: Breaking Down the Basics
To put it briefly, genetic hearing loss stems from alterations or mutations in a person’s DNA.
There are two important things to note within this basic definition:
- Genetic hearing loss is highly heterogeneous – There is no single gene that controls hearing health, and researchers continue to identify new genes associated with hearing loss.
- Genetic hearing loss doesn’t mean there’s a family history of hearing impairment – There can be a genetic cause of hearing loss, even if only one person in a family is affected. In fact, more than 90% of children born with hearing conditions have parents who have never experienced hearing loss. Out of that 90%, many of those children have a genetic component to their condition.
Experts tend to break down the gene variants that cause hearing loss into three categories: DFNA genes (dominant inheritance), DFNB genes (recessive inheritance), and DFNX genes (X-linked inheritance).
These categorizations help explain how hearing loss genes are passed down. DFNA genes, for example, are passed directly from parent to child and may appear in multiple generations. DFNB genes are also passed through families but are recessive and may skip one or more generations before anyone is impacted. With DFNX gene variants, relevant genes are only passed on to the X chromosome, and typically, only males in the family are at risk.
What many of these genes have in common is that they impact the structure, development, or function of the inner ear in some way or in the ways we process sound. Nevertheless, there’s still much to learn about the specifics behind different types of genetic hearing loss, and it’s not always possible to identify the exact gene or mutation at play.
Syndromic Hearing Loss vs. Non-Syndromic Hearing Loss
As previously mentioned, there are two different types of genetic hearing loss – syndromic and non-syndromic.
- Syndromic hearing loss occurs alongside other conditions. There are more than 400 known conditions that may be linked to genetic hearing loss, including many that affect parts of the body other than the ears.
- Non-syndromic hearing loss occurs without another condition. It is significantly more common and can vary in severity, even among members of the same family.
The DFNA, DFNB, and DFNX inheritance categorizations apply to both syndromic and non-syndromic hearing loss. However, non-syndromic genetic hearing loss can also be inherited through mitochondrial DNA, which is exclusively passed down from the mother.
Genetic Hearing Loss Treatment, Testing, and Prevention
There’s no such thing as a one-size-fits-all treatment plan in hearing health care. Instead, we carefully consider each individual’s unique situation, including the cause and severity of their hearing loss, their age, and, if relevant, any associated symptoms or conditions.
Hearing aids and cochlear implants are two of the most widely used treatments for genetic hearing loss. There is also promise in ongoing gene research therapy, wherein mutated genes are edited, replaced, or suppressed in order to relieve symptoms.
Hearing loss can have a huge impact on language development, so the sooner we can address it, the better. To ensure that patients get the right treatment at the optimal time, we highly recommend early testing and routine hearing screenings for people of all ages to identify potential hearing loss. Genetic counseling, a specialized healthcare service that provides individuals and families with information about genetic conditions, their inheritance patterns, and the associated risks, can also provide more information on the potential inherited cause of hearing loss and how it may evolve over time.
As for prevention, genetic hearing loss is unavoidable. However, you can take steps to mitigate its effects. Regularly monitor hearing health with a professional, and always work to protect your hearing, especially if you know you have a genetic risk. Loud noises, certain medications, and some infections can exacerbate genetic hearing loss and should be avoided if possible.
Want to Know More?
There is still so much to be discovered about genetic hearing loss. If you’re interested, keep an eye out for updates on our understanding of hereditary hearing loss and treatment advances, or talk to a hearing care professional. If you are in Albuquerque, Rio Rancho, or surrounding areas, Worth Hearing Center is here to work with you if you have any concerns about genetic hearing loss within your own family and can provide you with personalized guidance on hearing loss prevention and treatment.
While you’re here, be sure to explore HearingLoss.com resources, including hearing loss FAQs and the free online guided hearing experience, to get a better idea of the current state of your hearing. You can also search the hearing professional directory to find a provider near you who can help address any symptoms you may be having.
