Potential Links Between Childhood Hearing Loss and Genetics
Over the last few years, hearing loss has been on more researchers’ radars than ever before. This comes at no surprise either, with hearing loss being the third most common medical issue overall, and the number one most commonly reported workplace injury in the nation. From the prospect of potential hearing loss pills to increased hearing loss education efforts for children, we agree with hearing professionals who touted 2016 as the “year of the ear”.
We’re not done yet, either. Research findings out of Prince Edward Island – an Island off the southeastern coast of Canada – have been considered a medical breakthrough. Although the research team was only developed in 2015, PhD researcher Justin Pater and his team of amazing people discovered a gene mutation connected to early onset hearing loss in children.
Mutated CLDN14
CLDN14 is the name of the gene that “produces a protein that plays an essential role in maintaining inner ear cell structure and the transmission of auditory signals to the brain” (gazette.mun.ca). It is also the gene where the particular type of mutation discovered by Pater is located.
The CLDN14 gene mutations have been linked with children born with hearing loss across the world and for many years. What makes the mutation uncovered by Pater unique is that these children were actually born with normal hearing, and passed newborn hearing screens. It wasn’t until about age 3 or 4 that children started losing their ability to detect middle and high frequency sounds. The CLDN14 gene mutation has been identified as causing hearing loss at birth in Denmark, Iceland and The Netherlands. Pater’s research is the first time it has been known to cause early onset hearing loss in children born with normal hearing.
What makes this even more interesting is that in the providences of Newfoundland and Labrador (where the research was conducted) the gene mutation is much more common – effecting about 1% of the population.
How would losing your hearing at age 3 or 4 affect language development?
Ask a speech language pathologist what some of the most critical ages for language development are, and they’re likely to mention ages 3 to 4 somewhere on their list. Very early on, babies enjoy producing sounds and make them up on their own. However, young brains are programmed to attend to speech sounds and eventually attempt to mimic them. By about 9-18 months, most children have said their first word. Through continually listening to adult models through speech, singing and reading, children then begin stringing words together to form simple sentences by age two, and can usually say about 300 words and understand about 1,000. By age three, children use language not only to request or refuse, but to talk about past experiences or play pretend (childdevelopmentinfo.com). From there, language continues to develop and children begin to understand some of the rules of language by about 4 ½.
Because typical children heavily rely on their ability to hear in their language development, it is not difficult to see how a sudden decrease in hearing ability at age 3 or 4 would dramatically affect development in this area. To make matters worse, because these children passed their infant hearing screens, hearing loss may not be immediately considered.
This is where knowledge of the mutated gene can really help people. Audiologist Anne Griffin – a member of Pater’s research team – hopes to translate this new knowledge into the clinical setting, thus helping to identify children with this mutation early on, and hopefully implement strategies to reduce or eliminate language delays. (gazette.mun.ca).
I think my child may have hearing loss. What should I do?
When detected early, children with hearing loss can develop at normal rates when compared to their peers without hearing loss. Look for signs of normal speech and language development and make sure your child is hitting the milestones.
For a list of typical milestones for childhood social and language development, visit the National Institute on Deafness and Other Communications Disorders (NIDCD) website and take the “hearing and communicative development checklist”.
Reach out to us at Desert Valley Audiology or your local audiologist to schedule a hearing screen as soon as you can. Especially with children, the earlier hearing loss is detected, the earlier intervention strategies such as hearing aids and/or speech therapy can begin.
Desert Valley Audiology
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