DYSTROPHIA MYOTONICA, WITH SPECIAL REFERENCE TO ENDOCRINE FUNCTION (KLINEFELTER'S SYNDROME)*

Abstract

3 cases (2 brothers, and 1 female) of dystrophia myotonica, with necropsy in 1, are presented, with special emphasis on the endocrine features. Each had myotonia, muscle atrophy, cataracts, premature senility and hypogonadism. In the brothers, testicular biopsy revealed complete hyalinization of the seminiferous tubules with absence of spermatogonia and Sertoli cells. One had normal appearing Leydig cells and normal follicle-stimulating hormone secretion. The other brother had abnormal Leydig cells histologically and a high follicle-stimulating hormone secretion. The possibility of metabolism of FSH by Leydig cells is raised. It is logical to assume that the female had a genetic defect similar to that in the males and her endocrinopathy would thus be analogous. She presented all the features of ovarian agenesis. It is concluded that the hypogonadal syndrome of Klinefelter includes dystrophia myotonica among its list of causative conditions. The female presents the interesting association of the clinical features of ovarian agenesis and dystrophia myotonica.