Pendred Syndrome

A genetic association that accounts for as much as 10% of sensorineural deafness. Associated with a thyroid goiter but only occasionally hypothyroid. However, the hypothyroidism may be severe enough to cause mental and physical impairment. Age of onset is in infancy. It is not considered progressive, and it usually involves both ears.

Goiter-Deafness Syndrome; Goiter Sensorineural Deafness Syndrome.

First described by Pendred, in 1896, in two deaf sisters with goiter.

7:100,000 live births; M = F. Risk factors are familial.

Autosomal recessive with variable expression, involving the Pendrin (protein related to sulphate transport) gene, locus on chromosome 7q22-31.1

Gene mutation affects sulfate transport resulting in defective sulfated proteins in the thyroid, including thyroglobulin. Role of pendrin in cochlear development is not clear.

Clinical features; biochemical (normal or low T4 levels, high thyroid-stimulating hormone [TSH] levels, perchlorate discharge test positive, indicating defective organic binding of iodine in the thyroid gland, exaggerated response to thyrotropin-releasing hormone [TRH]).

Sensorineural hearing loss caused by cochlear malformation, is present at birth or detected in early infancy, and accounts for 10% of all childhood deafness. May have impaired vestibular dysfunction because of widened vestibular aqueduct. Goiter usually appears in middle or late childhood but can present in the newborn, causing airway obstruction and respiratory distress. The goiter is usually euthyroid but occasionally hypothyroidism may be severe. There is a very small risk of malignant neoplasm. Mental retardation has also been reported. Normal life span can be expected.

Thyroid function should be evaluated (TSH, T4 = high TSH and low T4 would confirm the presence of hypothyroidism). A perchlorate test should be performed to determine the extent of the thyroid dysfunction. However, it is not consistently positive in affected individuals. A medical consultation with the endocrine service is essential before any elective and emergency (if possible) surgical procedures.

The presence of hypothyroidism should be an indication to postpone elective surgery until corrected. Deafness and vestibular dysfunction contributes to a patient's anxiety. Preoperative evaluation of thyroid function and correction of hypothyroidism is necessary. Airway assessment is mandatory in the presence of large or long-standing goiter. Airway obstruction and respiratory distress in neonatal goiter may require emergency airway access. Possibility of postoperative tracheomalacia after excision of long-standing goiter.

Delayed metabolism of anesthetic drugs and opioids in case of hypothyroidism.