In this article Pendred's syndrome, which is the combination of - congenital goitre with deafmutism, is discussed. This type of goitre is due to a special enzymatic defect, involving 
a process of hormonogenesis, which is respon-· sible for the incorporation of iodide in the tyrosine molecule. 
A case of pendred's syndrome is presented 
in a 16-year-old girl. This girl has never been able to hear or speak, and has showed symp­toms of hypothyroidism since :the age of 13. 
The perchlorate test which is diagnostic and Pathognomonic for the disorder of the iodi­nation phase of the thyroid hoi·mone synthesis, was performed on this girl. The test revealed a result that was characteristic of the Pendred's syndrome. In addttion an audiogramm test showed an inability to percieve high tones.