1. Background

• first described by Pendred in 1896 in two deaf sisters with goiter
• also called Deafness-Goiter and Goiter-Sensorineural Deafness
• pendrin is closely related to a number of known sulphate transporters and thus a putative sulphate transporter (L.A. Everett et al., Nature Genetics 17(4):411 (1997))

2. Genetic Defect

• genetic mutation within the pendrin gene -> altered sulphate transport -> altered thyroxine synthesis -> hyperplasia of the thyroid gland -> goiter
• the role of altered pendrin function in hearing loss is unknown
• three mutations in the pendrin gene have been identified in patients with Pendred Syndrome (L.A. Everett et al., Nature Genetics 17(4):411 (1997))

1. Sensorineural Hearing Loss

• congenital or detected in early infancy
• usually profound leading to deafness
• tends to be non-progressive
• usually involves both ears
• high tone deafness with variable preservation of low tone hearing
• may have impaired vestibular function

2. Thyroid Manifestations

• goiter which usually appears in middle or late childhood but can present in the newborn period resulting in upper airway obstruction and respiratory distress
• usually euthyroid but occasionally hypothyroid
• hypothyroidism may be severe enough to cause mental and physical impairment

1. Thyroid Function

• normal or positive perchlorate discharge test
• moniter TSH and T4 on a regular basis for evidence of hypothyroidism (high TSH and low T4)

1. Supportive

• multidisciplinary approach
  • Paediatrics, Endocrinology, Audiology
  • speech therapy
  • hearing aids
  • genetic counselling

2. Medical

• exogenous thyroid hormone therapy for thyroid hyperplasia

3. Surgery

• common for the remnant of thyroid tissue to regrow after surgery thus multiple surgeries may be required

4. Prognosis

• normal life span anticipated if no significant complications
• minimal or no risk of malignant neoplasm of the thyroid gland

1. Rudolph, A.M., Rudolph's Pediatrics (19th Edition). p. 1630-1631. (1991).