A case of Klinefelter's syndrome with type 1 diabetes mellitus.

Klinefelter's syndrome (KS) is the most common sex chromosome disease in men. Classical features of the syndrome include a eunuchoidal body habitus, small testes and hypergonadotrophic hypogonadism. There has been an increased risk of diabetes mellitus and autoimmune disease for KS patients. This paper reports a case of KS in association with type 1 diabetes mellitus. The patient was a 21-year-old man, who has been confirmed by absolute insulin deficiency and positive IA-2 autoantibody. The hyperinsulinemic euglycemic clamp test indicated his insulin sensitivity in normal range, and his blood glucose was controlled well by the insulin therapy.