Reversible male infertility due to congenital adrenal hyperplasia

We have studied a patient who was azoospermic and infertile. The cause of his infertility was unusual and curable: untreated congenital adrenal hyperplasia resulting from a partial 21-hydroxylase deficiency. The diagnosis was suggested by the combination of small testes, elevated levels of testosterone and suppressed levels of gonadotrophins.