Pendred syndrome is a rare genetic disorder that is characterized by a combination of hearing loss and thyroid abnormalities. It is caused by mutations in the SLC26A4 gene, which encodes a protein called pendrin that is involved in the transport of ions in the body.
The primary features of Pendred syndrome include:
1. Sensorineural hearing loss: Typically, individuals with Pendred syndrome experience bilateral sensorineural hearing loss, which is present from early childhood or adolescence. The hearing loss may be progressive and can vary in severity.
2. Enlarged vestibular aqueduct: This is a characteristic radiologic finding in individuals with Pendred syndrome. The vestibular aqueduct is a bony canal in the inner ear that is abnormally enlarged in affected individuals.
3. Thyroid abnormalities: Pendred syndrome is also associated with thyroid abnormalities, such as a goiter (enlarged thyroid gland) and the development of thyroid nodules. Some individuals with Pendred syndrome may also have an increased risk of developing autoimmune thyroid disorders, such as Hashimoto's thyroiditis.
In addition to hearing loss and thyroid abnormalities, individuals with Pendred syndrome may also have inner ear malformations, balance problems, and speech and language delays. Management of Pendred syndrome typically involves hearing aids or cochlear implants for hearing loss and monitoring and treatment of thyroid abnormalities.