McCune-Albright syndrome as well as germline and somatic gain-of-function mutations of the TSH receptor gene, which may be associated with the presence of diffuse hyperplasia and toxic nodules, are also rare causes of thyrotoxicosis, as are TSH-secreting pituitary tumours and thyroid hormone resistance (Table 1).This review will focus on management of GD in childhood and of hyperthyroidism during the fetal and neonatal period. This evidence concerns the gene TSHR and hyperthyroidism.