What Is The Pendred Syndrome? How It cause Hearing Loss?

Ranjeet KumarReviewed by Mr. Ranjeet Kumar Sr. Audiologist, Speech Therapist & Cochlear Implant Specialist, BASLP on May 5th, 2020 written by Editorial Team

Pendred Syndrome is a genetic disorder that is associated with Hearing Loss. It can also affect the thyroid gland and this condition is named goiter. A thyroid gland is a butterfly-shaped organ that is located at the base of the neck. And, It produces the hormones.

You can purchase the latest hearing aids at a fair price through HearingSol, If you need any assistance or you have a query regarding Pendred Syndrome or Hearing Loss, feel free to call us at +91-9327901950. We are always here to help you.

Basically, this syndrome affects the body’s ability to make a protein called pendrin, which is important for normal functions of the inner ear and thyroid.

Those children who are born with this syndrome may be diagnosed with hearing loss at the time of birth. Hearing of these children worsen with time, if not treated properly.

In more cases, the children with this syndrome may have bilateral hearing loss. It means they have hearing loss in both ears.

How Is Pendred Syndrome Caused?

Pendred Syndrome is caused by the mutation of the gene called SLC26A4 or Pendred Syndrome gene which is found on a chromosome 7.

To be diagnosed with Pendred Syndrome, a child is required to inherit two mutated PDS genes, one from each parent.

Couples seek a doctor to perform genetic testing if they are concerned about their child for not being diagnosed with Pendred Syndrome.

A PDS gene produces a protein called pendrin which is found at a significant level in the thyroid gland. Pendrin transports chloride and iodide ions in and out of thyroid gland cells.

The normal transportation of chlorine and iodine ions is disrupted when the PDS gene contains a mutation, causing a Pendred Syndrome. This defected PDS gene may be responsible for some cases of deafness.

Symptoms Of Pendred Syndrome

  • Inner ear changes
  • Enlargement of the thyroid gland
  • Sensorineural Hearing loss present at the birth time
  • Balance problems due to altered function of the auditory system

Characteristics Of Pendred Syndrome

There are two characteristics of Pendred Syndrome-

  • Cochlea with too few turns:  Cochlea is a (spiral-shaped)part of the inner ear that converts sounds into electrical signals which are sent to the brain. The cochlea of a person with Pendred syndrome may only have one-and-a-half turns whereas a normal and healthy cochlea has two-and-a-half turns. However, not everyone with Pendred syndrome has an abnormal cochlea.
  • Enlarged Vestibular Aqueduct:  When the Vestibular Aqueduct is enlarged, the endolymphatic duct(balloon-shaped structure, end of the vestibular aqueduct) and sac grow large with excess fluid in comparison to their normal sizes.

Complications Of Pendred Syndrome

If not treated early, a child may have difficulty with speech and language skills. Medical evaluation as soon as a child is born, is necessary to diagnose any kind of complication with hearing to be able to treat it.

The only medical treatment available for sensorineural hearing loss is cochlear implantation. And to determine this type of Hearing Loss is possible only after a comprehensive medical examination of an individual.


1. Genetic testing

A doctor will suspect a person if he has severe or profound hearing loss from birth or early childhood, abnormality of the inner ear called an enlarged aqueduct, or abnormal thyroid levels or an enlarged thyroid.

All this is confirmed by genetic testing. Some labs will test for the gene changes in PDS genes and some labs with large panels of genes will test for as many reasons for hearing loss at one time.

2. Magnetic Resonance Imaging (MRI) or Computed Tomography (CT or CAT)

These are the inner ear imaging techniques that test for the two characteristics of Pendred syndrome i.e. cochlea with too many turns and enlargement of Vestibular Aqueduct.

3. Perchlorate Washout Test

This test is to check the proper functioning of the thyroid gland. Perchlorate displaces iodide without organification from the thyroid. There is a defect in the organification of iodine in Pendred’s syndrome.

In this test, radioactive iodine is given to the patient time is given until the iodine is captured by the thyroid. An oral perchlorate is administered.

As a result, those having Pendred’s syndrome will show a rapid loss of radioactive iodine from the thyroid.

Can Test For Pendred Syndrome Be Done Before Pregnancy?

Yes, the testing for Pendred Syndrome is available before pregnancy. This testing is called preimplantation genetic diagnosis (PGD).

This test can only be done if the changes in the genes which cause Pendred Syndrome in a family are known. PGD involves In Vitro Fertilization(IVF).

The embryos coming from IVF are tested for Pendred Syndrome and only the embryos found without a Pendred Syndrome are used for pregnancy.

Pendred Syndrome And Hearing Loss

Pendred’s Syndrome can cause sensorineural deafness/hearing impairment. The syndrome causes hearing impairment, which is associated with inner ear malformations such as an enlarged vestibular aqueduct (EVA) and Cochlea with too few turns.

The Vestibular Aqueduct is like a bony canal that connects the inner ear with the inside of the skull. There are some people who have an abnormality in the shape of the cochlea. In this case, the cochlea has too few turns than a cochlea of a normal hearing person.

As you know that the loss of hearing often happens suddenly. Some people with this syndrome have bilateral hearing loss. It means loss of hearing is in both ears.

Acquired Hearing Loss

Acquired Hearing Loss can show after birth and can happen at any time of illness or injury during childhood or adolescence. It can happen because of-

  • Ear infections
  • Head injury
  • Medicines that are toxic to the ear
  • Chickenpox
  • Flu
  • Loud noises like concerts and explosions
  • Measles
  • Meningitis

Pendred Syndrome Treatment

  • Cochlear Implant:  Cochlear Implant is an electronic device that provides a sense of sound to the person with a sensorineural hearing loss. This device is inserted surgically into the cochlea. It does not restore normal hearing, rather it helps a person to develop a new way of understanding speech. Children over 1 year of age and adults are eligible for the implant.
  • Hearing Aids:  Children having Pendred Syndrome are fitted with a Hearing Aid early in life.
  • Radioactive Iodine:  People having goiters large enough to cause swallowing and breathing problems, treatment includes the use of radioactive iodine to shrink the swelling.

Expert Suggestion

  • Individuals suffering from Pendred syndrome are recommended to avoid sports which may lead to head injury and could cause a progression in any existing hearing loss.
  • Always take head protection precaution whenever engaged in activities like cycling, skateboarding, horseback riding, or skiing.
  • Wear hearing aids.
  • Go for Cochlear implantation if hearing loss is at the severe to the profound level.
  • Avoid situations of rapid ear pressure change, such as scuba diving, or flying in small airplanes with unpressurized cabins.

You can purchase the latest hearing aids at a fair price through HearingSol, If you need any assistance or you have a query regarding Pendred Syndrome or Hearing Loss, feel free to call us at +91-9327901950. We are always here to help you.

Read also: Genetic Syndromes Associated with Hearing Loss

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