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
First described by Pendred, in 1896, in two deaf sisters
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
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.
Everett LA, Glaser B, Beck JC, et al: Pendred syndrome is caused by
mutations in a putative sulphate transporter gene (PDS). Nat Genet
Wintle RV, Choong YF, Laws DE: Unilateral corneal anesthesia and ulceration following
squint surgery in a child with Pendred Syndrome and bilateral sixth nerve palsy. B J