Myotonia dystrophica: Studies on gonadal function using luteinizing hormone-releasing hormone (LRH).

Eight men and four women with myotonia dystrophica were investigated. The gonadotropin responses to 100 mug luteinizing hormone-releasing hormone (LRH) were studied, and serum testosterone assayed. In the men with testicular atrophy a high basal follicle stimulating hormone was found with an exaggerated response to LRH. Although the mean basal luteinizing hormone was not significantly elevated, there was an excessive response to LRH, which was possibly conditioned by the lower mean testoerone levels in this group. This study provides biochemical indices of both the primary nature of the testicular damage and the disproportionately greater involvement of the seminiferous tubules. The pituitary-gonadal axis was normal in the women.