[The diagnosis of the Pendred syndrome in children by the perchlorate discharge test with 123I (author's transl)].

A modified method for the diagnosis of the Pendred Syndrome in children by the Perchlorate discharge test using 123I is described. The older child, who has the Pendred Syndrome and the obligatory hearing deficit, frequently has neither a goitre nor hypothyroidism, but other investigations (bone growth, scars and function tests) can also show changes. However a more certain diagnosis of this disorder in children is possible by the Perchlorate discharge test using 123I. The test using 131I is no longer justified in the face of more recent radiobiological knowledge.