Pendred syndrome is a genetic condition caused by mutations in the SLC26A4 gene. It was discovered by Dr. Vaughan Pendred, a general practitioner in England. His first patients with the syndrome were two sisters who had “bilateral sensorineural hearing loss with goiter.” Goiter refers to a swelling of the thyroid gland located in the neck. Some patients can struggle to breathe due to swelling in the throat. However, goiters are easy to monitor and treat. Most are removable. Not all patients with Pendred syndrome will develop goiters, but they are more likely to than the rest of the population.
The syndrome appears in very young children, usually newborn babies. Children born with it are either born with hearing loss or begin to lose their hearing before they reach three years old. Most children will find their hearing deteriorates over time, and they end up profoundly deaf. Hearing loss is usually sudden, but it can happen gradually in some instances. It’s more common to experience hearing loss in both ears (bilateral). In some cases, one ear can have worse hearing than the other. Pendred syndrome also affects balance.
Children born with Pendred syndrome are either born with hearing loss or begin to lose their hearing before they reach three years old.
An enlarged thyroid gland is another symptom of Pendred syndrome. Hormone levels are usually normal, although this doesn’t help much. People with Pendred syndrome are much more likely to develop goiters or swellings. Swellings in the throat can affect breathing and swallowing, especially if they increase in size.
Some babies start walking later. This is due to the slight delay in growth and development seen in children with the condition. Issues with the thyroid gland cause it, but mainly growth and development are unaffected. The most significant issues are hearing loss, balance issues, and sometimes goiters.
The SLC26A4 gene, which causes the condition, is responsible for around 5 – 10 percent of hereditary hearing loss, according to the U.S. National Institute of Health (NIH).
Read more: CHARGE syndrome and hearing loss
Pendred syndrome is diagnosed by ear, nose, and throat specialists or geneticists. Scans like MRI or CT may be used to explore the structure of the inner ear and the thyroid. Some patients may also have a cochlea with too few turns, displaying one and a half instead of the usual two and a half.
Scans may also reveal an enlarged vestibular aqueduct, which is part of the vestibular system responsible for balance.
There are a few options for treatment for Pendred syndrome, but they mainly revolve around living with the condition and its symptoms. For instance, hearing loss can be managed with hearing aids or cochlear implants. Difficulties learning to speak due to hearing loss can also be managed with speech therapy or sign language classes.
Medical experts often recommend avoiding head injuries and further damage to the hearing in patients who have some hearing left. Pendred syndrome will cause hearing to deteriorate further, so it is important to protect what hearing is left for as long as possible. Avoiding sudden pressure changes, such as scuba diving or hyperbaric chambers, is also important.
Some children can take a perchlorate washout test to check their thyroid function for thyroid problems. Regular thyroid tests are generally not offered, as the hormones the thyroid releases aren’t usually affected by Pendred syndrome, according to the NIH. Children or adults developing goiters should get them checked by a doctor regularly. They might need testing or removing. They will at least need monitoring for growth if the goiter begins to restrict breathing or swallowing. You may have to see an endocrinologist if the goiter becomes too large.
There isn’t currently a cure for Pendred syndrome, but medical experts can help you to manage the symptoms. Research is ongoing, and some teams are looking exclusively at the genetic basis of Pendred syndrome.