What are the symptoms? Children who are born with PS may begin to lose their hearing at birth or by the time they are three years old. The hearing loss is progressive, which means that a child will have less hearing over time and quite often is bilateral (meaning it affects both of the ears). Some individuals may become totally deaf (see entry Deafness). PS can affect the thyroid (a small gland in the front of the neck) by causing it to grow too large. An enlarged thyroid gland is known as a goiter. Learning difficulties may occur in individuals with PS due to congenital thyroid defects. In a few rare cases, this may also increase the risk of thyroid cancer (see entry Cancer). PS also may affect the vestibular system, which controls balance and some individuals with PS will show some vestibular weakness when their balance system is tested. What are the causes? PS is caused by changes, or mutations, to a gene known as SLC26A4 (also referred to as the PDS gene) on chromosome 7. The normal PDS gene makes a protein, called pendrin, which is found at significant levels in the thyroid gland only. How is it diagnosed? The diagnosing physician will assess a person’s hearing, inner ear structure and in some cases, the thyroid when diagnosing PS. They will look for two key characteristics of PS in the inner ear: 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 brainenlarged vestibular aqueduct. This is a bony canal that runs from the vestibule (a part of the inner ear between the cochlea and the semi-circular canals) to the inside of the skull. How is it treated? There is no cure for PS. Children with PS should start early treatment to learn skills that will help them communicate with reduced hearing, such as how to use a hearing aid or learning sign language and cued speech. Some individuals with PS will develop a hearing loss significant enough to be considered eligible for a cochlear implant. This is an electronic device that is surgically inserted into the cochlea and helps a person develop a new way of understanding speech. If a goiter becomes large, a person may have problems breathing and swallowing. A specialist will monitor a person’s goiter over time and decide what treatment is necessary. Inheritance patterns and prenatal diagnosis Inheritance patternsPS is inherited as an autosomal recessive trait. Most affected individuals have no family history of PS. However, when the altered gene for PS is detected in an individual, genetic counselling should be sought to discuss testing for carriers of the mutation in families and prenatal testing for future pregnancies. Prenatal diagnosisPrenatal testing may be available for individuals with PS where the genetic mutation in a family has been identified. Is there support? There is no support group for Pendred syndrome in the UK. Information and support for deafness associated with Pendred syndrome is provided by deafness support organisations (see entry Deafness). Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. To meet other families with disabled children, join Contact’s closed (private) Facebook group.