ABSTRACT
Although patients generally are euthyroid, some may be mildly hypothyroid. Mental retardation is noted in some, but not all cases of Pendred's syndrome. The hearing loss usually is congenital, bilateral, sensorineural, and moderate to profound, and it usually is worse in the high frequencies. There may be slow progression during childhood. More than 50% of these patients have a severe hearing deficit (108). Vestibular function frequently is abnormal, although vertigo is uncommon. Inheritance is autosomal recessive. Polytomography or CT scan may reveal a Mondini malformation of the cochlea (152,153).
