Pendred Syndrome

What is Pendred syndrome?

Pendred syndrome is a rare genetic disorder that may cause your child to be born with permanent hearing loss. Typically, the hearing loss is in both ears and gradually worsens. Children and young adults with Pendred syndrome may also develop a goiter (an enlarged thyroid gland) and (rarely) an underactive thyroid gland as a result of the goiter.

If your child has Pendred syndrome and hearing loss, their healthcare providers will work with you to help manage and treat your child’s symptoms as much as possible. They can recommend hearing technologies for your child and communication strategies so the hearing loss doesn’t impact their ability to learn and use language.

What are the symptoms of Pendred syndrome?

The main symptom of Pendred syndrome is hearing loss, which ranges in severity from moderate to profound. With moderate hearing loss, your child may be able to hear people talking but not understand what they’re saying. Profound hearing loss is the same as deafness.

Hearing loss is usually present at birth with Pendred syndrome. But it can also develop later in infancy or childhood.

Signs of hearing loss from Pendred syndrome may include:

• A baby who doesn’t startle when they hear a loud noise.
• A baby who doesn’t respond when you say their name.
• A baby who doesn’t say their first word by the age of 1.
• A child who doesn’t start speaking until later than their peers.
• A child who asks you to repeat yourself a lot.

Other signs of Pendred syndrome include:

• Balance issues, like taking longer to learn how to walk (uncommon).
• A goiter (most often appearing during adolescence or early adulthood).
• Hypothyroidism (uncommon).

What causes Pendred syndrome?

Pendred syndrome typically involves an inherited genetic mutation (change) on the SLC26A4 gene. This gene helps your body make pendrin, a protein that plays a role in your hearing and thyroid function. Your thyroid releases hormones that help regulate how your body uses energy (metabolism).

Problems with pendrin can cause the hearing structures within your child’s inner ear to develop abnormally. This can lead to sensorineural hearing loss. “Sensorineural” means that the hearing loss involves problems with hearing structures in the inner ear specifically and is permanent. The problems may include:

• Enlarged vestibular aqueducts (EVAs): Your vestibular aqueducts are bony canals that connect your inner ear to your skull. Many people with enlarged aqueducts experience hearing loss.
• A cochlea with too few “turns”: Your cochlea is the innermost part of your hearing system. It’s a spiral-shaped structure that typically has 2 and 3/4 turns. With Pendred syndrome, your child may have fewer turns in the spiral than someone with a normal cochlea. This can be associated with hearing loss.

Pendrin also plays a role in how your thyroid works. Issues with your thyroid can cause it to become enlarged (a goiter) and prevent it from making enough hormones.

How is Pendred syndrome inherited?

Children inherit the genetic mutation for Pendred syndrome in an autosomal recessive pattern. This means that, to experience symptoms, a child would have to inherit two copies of the mutation — one from each biological parent.

With Pendred syndrome, parents are carriers. They both carry one mutated gene and one normal gene. While the normal gene prevents the parents from having Pendred syndrome, there’s a 25% chance of having a baby with the condition.

How is Pendred syndrome diagnosed?

Hearing screenings are routine tests that can help healthcare providers detect hearing issues in newborns. If a hearing screening reveals signs of hearing loss, your newborn will need additional tests to diagnose hearing loss and further tests to diagnose Pendred syndrome. Or you may schedule an appointment with a provider if your child exhibits hearing loss symptoms. You’ll likely need to see an otolaryngologist (ENT) or a genetics specialist for a diagnosis.

During the appointment, the provider may ask questions about your child’s hearing loss, like when you first noticed it. They may ask about your family’s history of hearing loss. As Pendred syndrome is an inherited disorder, it’s likely that a relative also had or has hearing issues.

Tests to help diagnose Pendred syndrome include:

• Hearing tests: Providers perform tests like otoacoustic emissions (OAE) and auditory brainstem response (ABR) tests to evaluate inner ear function and auditory pathways. Your child may need other routine tests as they get older to check for hearing loss.
• Imaging scans: A CT scan or MRI can show abnormal inner ear structures associated with Pendred syndrome, including enlarged vestibular aqueducts and an atypical cochlea.
• Genetic testing: Blood tests that detect the mutation on the SLC26A4 gene can confirm a diagnosis.

Your child may also need to see an endocrinologist to check for thyroid problems if they have a goiter.

How is Pendred syndrome treated?

Although there isn’t a cure for Pendred syndrome, there are options available to manage it. Treatment depends on many things, like the type of abnormalities in your child’s inner ear and the severity of your child’s hearing loss. Treatment options for Pendred syndrome include:

• Education: Your child may need to learn ways to communicate so that they don’t have to rely solely on their hearing to interact with others.
• Hearing devices: Your child may need hearing aids or a cochlear implant to help them hear better. These devices significantly help and will typically give your child access to sound at a minimum. An audiologist will review and recommend appropriate hearing technology for your child in collaboration with an otolaryngologist.
• Thyroid treatments: Your child may need to take thyroid supplements if they have an underactive thyroid. They may need surgery to remove a goiter (thyroidectomy) depending on its size.

What can I expect if my child has Pendred syndrome?

Pendred syndrome often leads to progressive hearing loss. Some children eventually lose all or most of their hearing. Still, the severity varies. Many children function well and can hear at normal levels with the help of hearing aids or cochlear implants. Your child’s care team can advise you on what treatments may help your child’s hearing.

Most importantly, early identification and treatment can help your child learn ways to communicate with others and reach milestones at the same rate as their peers. Pendred syndrome is a lifelong condition, but this doesn’t mean it has to prevent your child from understanding others or expressing themselves.

How do I take care of my child?

If your child has Pendred syndrome, it’s essential that you take precautions to protect them from head injuries, as you would any child. For example, using head protection with helmets can minimize the risk of sudden hearing loss from trauma when biking.

When should I see a healthcare provider?

Schedule an appointment with your child’s provider if you’re noticing signs of hearing loss — regardless of whether the cause is Pendred syndrome or something else. The earlier your child receives a diagnosis, the sooner there can be interventions to help manage and treat hearing loss.

What questions should I ask my child’s healthcare provider?

Questions to ask include:

• What providers will make up my child’s care team?
• What signs should alert me that my child’s hearing is worsening?
• What treatments are available?
• What treatment timeline do you suggest?
• What activities may put my child at risk of further hearing loss?
• What resources are available to help children and parents cope with childhood hearing loss?