Pendred syndrome is an autosomal recessive inherited disorder. Obligatory features are profound
deafness in childhood and defective organic binding of
iodine in the thyroid gland. Therefore,
goiter is a common symptom. Hypoplasia of the cochlea is another feature. Recently, the gene for
Pendred syndrome was identified. We describe a boy whose
sensorineural hearing loss in both ears progressed rapidly from about 50 to 60 dB at the age of 3 years and 3 months to more than 100 dB at the age of 4 years and 4 months. This loss was preceded by a medical history of a progressive
hearing loss. The progressive nature of the
hearing loss motivated a search for the cause. Dysplasia of the cochlea and a widened vestibular aqueduct were found. The results of thyroid function tests were normal, but he had an elevated level of
thyroglobulin. The diagnosis of
Pendred syndrome was confirmed by the positive results of a
potassium perchlorate test, indicating defective organic binding of
iodine in the thyroid gland. It is possible that the widened vestibular aqueduct was responsible for the increase in the
hearing impairment. Aside from the
branchio-otorenal syndrome,
Pendred syndrome is the only other known
genetic disorder with a widened vestibular aqueduct. If a child has progressive sensorineural
deafness and a widened vestibular aqueduct, it is important to consider a diagnosis of
Pendred syndrome. A widened vestibular aqueduct may help to elucidate the pathophysiologic characteristics of
hearing loss in these genetic types of
deafness in childhood.