An activating mutation of the thyrotropin receptor gene in hereditary non-autoimmune hyperthyroidism.

The thyroid stimulating hormone (TSH) receptor gene displays a diverse spectrum of activating and inactivating mutations. We report a germline activating mutation M463V of the TSH receptor gene in two siblings with hereditary non-autoimmune hyperthyroidism. The onset of disease in the affected members of the pedigree occurred during childhood or adolescence. The significance of diagnosing activating TSHR mutations lies in therapeutic management and genetic counseling; thyroid ablation is advocated as first line treatment.