U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES ∙ National Institutes of Health 

NIDCD Fact Sheet | Hearing and Balance 

Pendred Syndrome 

What is Pendred syndrome? 

Pendred syndrome is a genetic disorder that causes early 

hearing loss in children. It also can affect the thyroid 

gland and sometimes creates problems with balance. The 

syndrome is named after Vaughan Pendred, the physician 

who first described people with the disorder. 

Children who are born with Pendred syndrome may begin 

to lose their hearing at birth or by the time they are 3 years 

old. Usually, their hearing will worsen over time. The loss of 

hearing often happens suddenly, although some individuals 

will later regain some hearing. Eventually, some children 

with Pendred syndrome become totally deaf. 

Almost all children with Pendred syndrome have bilateral 

hearing loss, which means hearing loss in both ears, although 

one ear may have more hearing loss than the other. 

Childhood hearing loss has many causes. Researchers 

believe that in the United States 50 to 60 percent of cases 

are due to genetic causes, and 40 to 50 percent of cases 

result from environmental causes. Health care professionals 

use different clues, such as when the hearing loss begins 

and whether there are anatomical differences in the ears, 

to help determine whether a child has Pendred syndrome 

or some other type of progressive deafness. 

How does Pendred syndrome affect 

other parts of the body? 

Pendred syndrome can make the thyroid gland grow 

larger. An enlarged thyroid gland is called a goiter. The 

thyroid is a small, butterfly-shaped gland in the front of 

the neck, just above the collarbones. The thyroid plays 

a major role in how the body uses energy from food. In 

children, the thyroid is important for normal growth and 

development. Children with Pendred syndrome, however, 

rarely have problems growing and developing properly, 

even if their thyroid is affected. Their levels of thyroid 

hormones are usually normal. 

People with Pendred syndrome are significantly more 

likely than the general population to develop a goiter in 

their lifetime, although not everyone who has Pendred 

syndrome gets a goiter. The typical age for a goiter to 

develop is in adolescence or early adulthood. If a goiter 

becomes large, there may be problems with breathing 

and swallowing. In this case, a health professional 

should check the goiter and decide whether treatment is 

necessary. People with Pendred syndrome may need to 

visit an endocrinologist, who is a specially trained doctor 

familiar with diseases and disorders that involve the 

endocrine system, including the thyroid gland. 

Pendred syndrome also can affect the vestibular system, 

which controls balance. Some people with Pendred 

syndrome will show vestibular weakness when their 

balance is tested. However, the brain is very good at 

making up for a weak vestibular system, and most 

children and adults with Pendred syndrome don’t have 

a problem with their balance or have difficulty doing 

routine tasks. Some babies with Pendred syndrome may 

start walking later than other babies, however. 

Scientists don’t know why some people with Pendred 

syndrome develop a goiter or have balance problems and 

others don’t. 

NIDCD...Improving the lives of people with communication disorders 
What causes Pendred syndrome? 

Pendred syndrome can be caused by changes, or mutations, 

in a gene called SLC26A4 (formerly known as the PDS gene) 

on chromosome 7. Because it is a recessive trait, a child needs 

to inherit two mutated SLC26A4 genes—one from each 

parent—to have Pendred syndrome. Since the child’s parents 

are only carriers of a mutation in the SLC26A4 gene, there 

are no health implications for them. 

Couples who are concerned that they could pass Pendred 

syndrome to their children might want to seek genetic 

testing. A possible sign that someone might be a carrier of 

a mutated SLC26A4 gene is a family history of early hearing 

loss. Another sign is a family member who has both a goiter 

and hearing loss. However, often there is no family history of 

Pendred syndrome in the families of children who have the 

disorder. A mutation in the SLC26A4 gene can be determined 

by genetic testing of a blood sample. 

The decision to have a genetic test is complicated. Most 

people talk with a genetic counselor trained to help them 

weigh the medical, emotional, and ethical considerations 

of testing. A genetic counselor is a health professional who 

provides information and support to people (and their 

families) who have a genetic disorder or who are at risk for a 

genetic disorder. 

Credit: NIH Medical Arts 

The inner ear 

How is Pendred syndrome diagnosed? 

An otolaryngologist (a doctor who specializes in diseases 

of the ear, nose, throat, head, and neck) or a clinical 

geneticist will consider hearing loss, inner ear structures, 

and sometimes the thyroid in diagnosing Pendred 

syndrome. He or she also will evaluate the timing, 

amount, and pattern of hearing loss and ask questions, 

such as “When did the hearing loss start?,” “Has it 

worsened over time?,” and “Did it happen suddenly or 

in stages?” Early hearing loss is one of the most common 

characteristics of Pendred syndrome; however, this 

symptom alone doesn’t mean a child has the condition. 

The specialist will use inner ear imaging techniques, such 

as magnetic resonance imaging (MRI) or a computed 

tomography (CT) scan, to look for two characteristics of 

Pendred syndrome. One characteristic might be a cochlea 

with too few turns. The cochlea is the spiral-shaped 

part of the inner ear that converts sound into electrical 

signals that are sent to the brain. A healthy cochlea has 

two-and-a-half turns, but the cochlea of a person with 

Pendred syndrome may have only one-and-a-half turns. 

Not everyone with Pendred syndrome, however, has an 

abnormal cochlea. 

A second characteristic of Pendred syndrome is an 

enlarged vestibular aqueduct (see figure). The vestibular 

aqueduct is a bony canal that runs from the vestibule 

(a part of the inner ear between the cochlea and the 

semicircular canals) to the inside of the skull. Inside 

the vestibular aqueduct is a fluid-filled tube called the 

endolymphatic duct, which ends at the balloon-shaped 

endolymphatic sac. The endolymphatic duct and sac 

usually are also enlarged. 

Experts don’t recommend testing thyroid hormone 

levels in children with Pendred syndrome, since levels 

are usually normal. Some children might be given a 

“perchlorate washout test,” a test that determines 

whether the thyroid is functioning properly. Although 

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this test is probably the best test for determining thyroid 

function in Pendred syndrome, it isn’t used often and 

has largely been replaced by genetic testing. People 

who have developed a goiter may be referred to an 

endocrinologist, a doctor who specializes in glandular 

disorders, to determine whether the goiter is due 

to Pendred syndrome or to another cause. Goiter is 

a common feature of Pendred syndrome, but many 

individuals who develop a goiter don’t have Pendred 

syndrome. Conversely, many people who have Pendred 

syndrome never develop a goiter. 

How common is Pendred syndrome? 

The SLC26A4 gene, which causes Pendred syndrome, 

accounts for about 5 to 10 percent of hereditary 

hearing loss. As researchers gain more knowledge about 

the syndrome and its features, they hope to improve 

doctors’ ability to detect and diagnose the disorder. 

Can Pendred syndrome be treated? 

Treatment options for Pendred syndrome are available. 

Because the syndrome is inherited and can involve 

thyroid and balance problems, many specialists may 

be involved in treatment, including a primary care 

physician, an audiologist, an endocrinologist, a clinical 

geneticist, a genetic counselor, an otolaryngologist, and 

a speech-language pathologist. 

To reduce the likelihood of hearing loss progression, 

children and adults with Pendred syndrome should avoid 

contact sports that might lead to head injury; wear head 

protection when engaged in activities such as bicycle 

riding and skiing that might lead to head injury; and avoid 

situations that can lead to barotrauma (extreme, rapid 

changes in pressure), such as scuba diving or hyperbaric 

oxygen treatment. 

Pendred syndrome isn’t curable, but a medical team will 

work together to encourage informed choices about 

treatment options. They also can help people prepare 

for increased hearing loss and other possible long-term 

consequences of the syndrome. 

Children with Pendred syndrome should start early 

treatment to gain communication skills, such as learning 

sign language or cued speech or learning to use a 

hearing aid. Most people with Pendred syndrome will 

have hearing loss significant enough to be considered 

eligible for a cochlear implant. A cochlear implant is 

an electronic device that is surgically inserted into the 

cochlea. While a cochlear implant doesn’t restore or 

create normal hearing, it bypasses injured areas of the 

ear to provide a sense of hearing in the brain. Children 

and adults are eligible to receive an implant. For more 

information, see the NIDCD fact sheet “Cochlear 

Implants” at http://www.nidcd.nih.gov/health/hearing/

pages/coch.aspx. 

People with Pendred syndrome who develop a goiter 

need to have it checked regularly. The type of goiter 

found in Pendred syndrome is unusual because even 

though it grows in size, it still continues to make normal 

amounts of thyroid hormone. Such a goiter often is 

called a euthyroid goiter. 

What research is being conducted? 

The NIDCD is funding researchers who are working to 

understand hearing loss caused by inherited syndromes 

such as Pendred syndrome, as well as from other causes. 

Researchers also are looking carefully at the characteristics 

of the disorder and how the syndrome might cause 

problems in different parts of the body, such as the thyroid 

and inner ear. 

Scientists continue to study the genetic basis of Pendred 

syndrome. The protein that the SLC26A4 gene makes, 

called pendrin, is found in the inner ear, kidney, and thyroid 

gland. Researchers have identified more than 150 deafnesscausing mutations or alterations of this gene. 

By studying mice, scientists are gaining a greater 

understanding of how an abnormal SLC26A4 gene 

affects the form and function of different parts of 

the body. For example, by studying the inner ears of 

mice with SLC26A4 mutations, scientists now realize 

that the enlarged vestibular aqueduct associated with 

Pendred syndrome is not caused by a sudden stop in 

the normal development of the ear. Studies such as this 

are important because they help scientists rule out some 

causes of a disorder while helping to identify areas in 

need of more research. Researchers are hopeful that 

these studies eventually will lead to therapies that can 

target the basic causes of the condition. 

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Where can I find additional 

information about Pendred syndrome? 

The NIDCD maintains a directory of organizations that 

provide information on the normal and disordered 

processes of hearing, balance, taste, smell, voice, 

speech, and language. Visit the NIDCD website at 

http://www.nidcd.nih.gov to search the directory. 

Use the following keywords to help you find 

organizations that can answer questions and provide 

printed or electronic information on Pendred syndrome: 

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Hereditary hearing loss 

Genetic diseases/disorders 

Early identification of hearing loss in children 

More NIDCD fact sheets on Hearing and Balance: 

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Ear Infections in Children 

Enlarged Vestibular Aqueducts and Childhood 

Hearing Loss 

It’s Important to Have Your Baby’s Hearing Screened 

Usher Syndrome 

Vestibular Schwannoma (Acoustic Neuroma) and 

Neurofibromatosis 

Your Baby’s Hearing and Communicative Development 

Checklist 

Visit the NIDCD website at http://www.nidcd.nih.gov to 

read, print, or download fact sheets. 

For more information, additional addresses and phone 

numbers, or a printed list of organizations, contact us at: 

The NIDCD Information Clearinghouse 

1 Communication Avenue 

Bethesda, MD 20892-3456 

Toll-free Voice: (800) 241-1044 

Toll-free TTY: (800) 241-1055 

Fax: (301) 770-8977 

Email: nidcdinfo@nidcd.nih.gov 

http://www.nidcd.nih.gov

 Follow the NIDCD on Twitter at @NIDCD 

The NIDCD supports and conducts research and 

research training on the normal and disordered 

processes of hearing, balance, taste, smell, voice, 

speech, and language and provides health information, 

based upon scientific discovery, to the public. 

Pendred Syndrome 

NIH Pub. No. 13-5875 

Updated November 2012 

NIH...Turning Discovery Into Health®