Pendred syndrome (PDS) is a common form of syndromic deafness. At least 5% of the total cases with congenital deafness are PDS. Typical PDS has the association of congenital bilateral neurosensory deafness, thyroid goiter, cochleovestibular malformation and potential vestibular dysfunction. The severity of the symptoms and the age of onset vary from case to case. Deafness often appears at birth, but it may develop in late infancy or early childhood. Sometimes, deafness is asymmetrical or fluctuant and often it is progressive. Abnormal bones of the inner ear can be observed in PDS. Thyroid status varies from euthyroid (goiter) to hypothyrodism. Goiter is secondary to abnormal iodine transport across the thyrocyte and it develops most commonly during adolescence. Incidence differs according to geographic location with a range between 1/100,000 births and 10/100,000 births. Audio-prosthetic management of deafness can be helpful and if the goiter becomes compressive because of excessive size, a thyroidectomy must be performed.

Pendred Syndrome (PDS) is inherited as an autosomal recessive trait. The only gene known to be associated with PDS is the solute carrier family 26, member 4 gene (SLC26A4), or PDS gene. The normal PDS gene makes a protein (pendrin) that is found at significant levels only in the thyroid. Pendrin transports anions, particularly chloride (Cl-) and iodide (I-), into and out of the cells. This action is important for thyroid function and inner ear development. Alteration in PDS gene will impair the function of pendrin leading to thyroid malfunction and improper development of the ear. Mutations in PDS gene are found in more than 90% of typical cases and they differ according to ethnic group.