According to the U.S. Centers for Disease Control and Prevention, about one in every 500 infants in the United States is born with hearing loss or develops it in early childhood. If you or your partner has hearing loss, and if you are pregnant or considering expanding the family, it’s natural to wonder if your child could inherit hearing loss. It is possible; in fact, it’s also possible for a child with two hearing parents to be born with hearing loss. While there are non-genetic causes of infant hearing loss (such as infections during pregnancy or after birth), almost 80% of infants with hearing loss acquire it due to genetic causes.
Genetic Hearing Loss
To start, not all forms of hearing loss in adults are genetic. In those cases, hearing loss would not be inherited. For example, if you have noise-induced hearing loss, the cause was environmental, not genetic; therefore, you would not pass hearing loss down to your child.
Genetic hearing loss, on the other hand, is caused by certain genes in our cells. Genes don’t just dictate our eye and hair color—they provide instructions to the body on how to develop and function, like a blueprint. Gene mutations are changes or errors in the genes, and they can alter how they work or provide faulty instructions. Both genes and gene mutations are passed from parent to child.
Hearing loss passed down genetically can be sorted into two main categories: syndromic and non-syndromic. Both types are dictated by the child’s genes, but in different ways.
Syndromic Hearing Loss
Syndromic hearing loss occurs when an infant’s hearing loss is associated with and/or caused by another medical condition. Some syndromes associated with syndromic genetic hearing loss include Pendred syndrome, Waardenburg syndrome, Nager syndrome and Miller syndrome.
If you had genetic testing done during pregnancy or learned at birth that your baby has a syndrome, it’s worth investigating if syndromic hearing loss could occur simultaneously with your baby’s syndrome.
Non-Syndromic Hearing Loss
Non-syndromic hearing loss is much more common than syndromic hearing loss. It occurs with no other medical conditions, symptoms or syndromes. Rather, a gene or gene mutation directly caused hearing loss. Here are some examples of how that would occur.
- A change in a gene known as the GJB2 gene is known to cause hearing loss. This gene contains instructions to produce a specific protein that enables the inner ear to function correctly.
- A gene known as STRC is also linked to hearing loss. The STRC gene provides the instructions for making a protein found in the inner ear called stereocilin, which is imperative in the hearing process.
Mutations to these two genes are the most common cause of non-syndromic hearing loss, but there are many others. Scientists have identified over 125 genes associated with non-syndromic hearing loss.
Hearing Loss Testing in Children
Performing hearing tests on infants after birth in the hospital or birthing center is standard. Hearing screenings for infants are painless and easy; often, the baby sleeps through it. If your infant did not pass their first screening, a follow-up test will be scheduled before they reach three months of age.
Early detection is essential for managing your child’s hearing loss. You and your infant’s hearing health team can determine what programs or resources are needed to work with their individual hearing needs. This could include pediatric hearing aids, connecting with a therapist for communication and development and joining support groups. Call Wilmington Audiology Services today; we’ll be on this journey with you and your child as you navigate hearing loss.