Although 5% of all cases of congenital deafness are caused by Pendred'
s syndrome, there are few reports in the literature. Seven patients wi
th Pendred's syndrome in three families living in the same village wer
e detected. For that reason, the syndrome is reviewed in light of the
literature. The sex distribution of the patients with Pendred's syndro
me and their families was recorded. We tested for thyroxine, triiodoth
yronine, thyroid-stimulating hormone, triiodothyronine resin uptake, a
nd perchlorate, and performed caloric testing. In one patient, subtota
l thyroidectomy was performed. In the histopathologic study, a thyroid
nodule filled with colloid was found. Chromosome studies showed no an
omalies in any patient. Five of the patients were deaf-mutes. We obser
ved that the parents were cousins in all three families. These familie
s also had healthy children, and the existence of the syndrome in both
sexes points to an autosomal recessive trait.