Is Hearing Loss Genetic?
The short answer is yes. Hearing loss can run in families.
When hearing loss is passed down from parents, it’s known as genetic hearing loss.
It’s estimated that 50-60% of all hearing loss in babies is due to genetic causes. There are hundreds of genes known to cause genetic hearing loss and deafness.
Today we will discuss the two types of genetic hearing loss, how they’re tested and what treatment is available.
What Are the Types of Genetic Hearing Loss?
Syndromic hearing loss
This type of hearing loss makes up 15-30% of all genetic cases.
Patients who have this type of hearing loss also have other disorders in the body, such as Usher syndrome, Stickler syndrome, Waardenburg syndrome and neurofibromatosis type two. All of these disorders have symptoms that can vary from mild to severe.
Non-syndromic hearing loss
On the other hand, non-syndromic hearing loss accounts for the remaining 70% of genetic hearing loss. It occurs when there are no other signs or medical problems present.
The most common type of non-syndromic hearing loss in babies is connexin 26 or GJB2.
Since hearing loss is known to run in the family, audiologists and other health professionals will routinely ask if there is anyone in the family who has permanent hearing loss. Audiologists will identify babies with a risk factor, and they will be monitored carefully and followed up more regularly than other babies.
How Can Hearing Loss be Identified in Babies?
Audiologists test the hearing of all people, including babies.
All newborn babies will have their hearing screen shortly after birth. If they fail a hearing screen, they will be referred to a specialist paediatric audiologist for complete diagnostic testing. The audiologist will test the baby while it’s sleeping.
If an audiologist diagnoses a hearing loss, further testing will be required to determine the cause of the hearing loss.
The audiologist will recommend a referral to an ENT Specialist to do a physical examination, family history, temporal bone scanning and molecular genetic testing.
What is genetic testing?
Genetic testing involves looking at a person’s DNA to see if certain mutations are present.
A person’s DNA sample is usually taken from a small blood sample or cheek cells inside a person’s mouth.
As not all the genes that cause hearing loss are known, even if the condition runs in the family, it may not be possible to find the mutation that causes it. Some tests are hard to do. For example, it is harder to study the whole gene when it’s bigger. Sometimes, it’s not possible to tell if a mutation has caused a condition or if it’s just a coincidence.
Does Hearing Loss Always Pass on to Babies?
No, not all the time. Normal hearing babies can be born to a parent with hearing loss. The opposite can also occur.
In fact, most babies with hearing loss are born to parents who can hear.
What else can cause hearing loss in babies?
There are many non-genetic causes of hearing loss, which make up around 40-50% of hearing loss in babies, including:
- Certain infections the mother has during pregnancy
- Infections the newborn baby has
- Complications during or after birth
- Certain medications
Sometimes, genes and environment can work together to cause hearing loss. Although, even after testing, the cause of hearing loss is still unknown for many babies.
Who is Involved in The Treatment of Hearing Loss?
Depending on the severity of your hearing loss and other conditions, it is likely that many of the following healthcare professionals will be involved:
The audiologist will be involved in the diagnosis of your hearing loss. They will perform a comprehensive hearing assessment to establish the level and severity of hearing loss.
Your audiologist can also prescribe and fit hearing aids so babies can develop their speech and language appropriately.
An ENT is a doctor who specialises in the health and anatomy of the ear. They also provide necessary medical assistance, including investigating the cause of the hearing loss through imagery, blood tests, genetic tests and cheek swabs.
- Genetic counsellor
A genetic counsellor helps parents and family members understand their genetic results and how they impact their future family planning.
- Speech therapist
A speech therapist will aid in speech and language development.
- Cochlear implant team
When a hearing loss is diagnosed as severe by an audiologist, a referral to the cochlear implant clinic will be made.
How Can an Audiologist Help with Hearing Loss?
If you or your baby has been diagnosed with permanent hearing loss that requires hearing aids or implantation, you will see audiologists for the rest of your life.
Your audiologist will be the one to perform your annual hearing checks and will also adjust your hearing aids if need be.
Babies diagnosed with hearing loss will commonly see an audiologist who specialises in infants. This audiologist will confirm all the test results and establish the baby’s level of hearing loss.
A paediatric audiologist will fit and adjust the baby’s hearing aids. Regular hearing aid adjustments and maintenance will be required as the child grows.
If your baby is diagnosed with hearing loss that is severe to profound and a referral for a cochlear implant is recommended, an audiologist will be part of the team of specialists who will look after your child.
Hearing loss can be passed on from parents to their children, but this is not always the case.
If you or someone in your family has noticed a change in hearing, it’s best to see an audiologist as soon as possible for a hearing test. Your audiologist will help guide you through the various hearing stages of your or your family member’s life.
At Attune Hearing, we offer comprehensive hearing assessments to determine what type of hearing loss you have and the severity of it. To book an appointment, visit our website or call us on 1300 736 702.