Male pseudohermaphroditism due to 5 alpha-reductase deficiency. Ultrastructure of the gonads.

We report here the results of the endocrine studies and the morphological findings of the gonads in two male pseudohermaphrodite siblings with 5 alpha-reductase deficiency. Basal levels of luteinizing hormone, follicle-stimulating hormone, and prolactin were elevated and rose to very high levels in response to gonadotropin-releasing hormone and thyrotropin-releasing hormone,, when compared to those in normal males, while thyroid-stimulating hormone response was normal. Serum testosterone levels were within the normal range, and estradiol values were modestly elevated. Diagnosis was confirmed by lack of conversion of 3H-testoterone to 3H-dihydrotestosterone by fibroblasts taken from perineal skin. Pathologic examination of the testes in both patients disclosed tubular atrophy and complete arrest of spermatogenesis, with numberous hyperplastic Leydig cells containing large Reinke crystalloids.