Pendred Syndrome

**Semantic type:** Disease or Syndrome

**Definition:** A condition associated with reduced export of iodide across the apical membrane of the follicular cells of the thyroid gland that may progress to hypothyroidism. Pendred syndrome is associated with an increased risk of goiter and sensorineural hearing loss due to malformations of the inner ear (vestibular system). Inactivating mutations in the SLC26A4 gene encoding the pendrin transport protein are responsible for the condition.