Graves’ hyperthyroidism, an autoimmune disorder, has an annual incidence of 1 in 10 000 adolescents (~700 per year) in the UK.1 The standard first-line treatment is the antithyroid drug (ATD) carbimazole (CBZ), which prevents the thyroid gland from manufacturing thyroid hormone and has an immunomodulatory effect.2 While CBZ will render most patients biochemically euthyroid in appropriate doses, only 50% of adults will remit following a standard 2-year course of ATD. The gene discussed is TG; the disease is Graves disease.