[Resistance to thyroid hormone - goiter and attention deficit-hyperactivity disorder as main manifestation]

Two siblings with goiter and attention deficit-hyperactivity disorder were presented. Earlier laboratory tests showed increased serum levels of thyroid hormones in association with non-suppressed serum levels of thyrotropin (TSH) in both children. Because hyperthyroidism caused by inappropriate secretion of thyrotropin was suspected, a cerebral MRI was performed. A pituitary adenoma was excluded in both children. Before antithyroid drug treatment was initiated, both patients were referred to our hospital. Careful medical history, clinical examination of the patients and careful interpretation of the laboratory results finally led to the diagnosis resistance to thyroid hormone (RTH).

Thyroid hormone serum levels were elevated in both children, while serum TSH was within the normal range. Molecular analysis confirmed the diagnosis of RTH.

Thyrostatic treatment was not initiated.

Careful medical history, correct interpretation of laboratory results, comprehensive clinical examination and molecular genetic analysis are important in the diagnosis of RTH.