A case of Graves' disease associated with Turner's syndrome

It is becoming increasingly evident that adults with Turner’s syndrome are susceptible to endocrine autoimmunity. An increased prevalence of thyroid autoantibodies and hypothyroidism in patients with Turner’s syndrome has been reported, but the involvement of Graves’ disease in these patients is relatively rare. We describe a case of Graves’ disease associated with Turner’s syndrome. A 28-year-old woman was referred for diffuse anterior neck swelling and palpitation. She had been diagnosed with Turner’s syndrome with monosomy 45,X before the age of 9 years and she took estrogen together with progesterone. The physical examination revealed a firm, non-tender goiter. The T3 level was 632 ng/dL, the free T4 level was 5.68 ng/dL, the TSH level was 0.02 µIU/mL, the % of TSH-binding inhibiting immunoglobulin was 24% and the anti-thyroid autoantibodies were positive. The radioactive iodine uptake was increased. Therefore, she was diagnosed as having Graves’ disease.