ACTH stimulation tests in women with hirsutism

To the Editor: The paper by Siegel et al. (Sept. 27 issue)¹ raises a question about the interpretation of the results of ACTH stimulation tests in women with hirsutism. An excessive response (i.e., an increase to a value >2 SD above the mean in normal women) of either plasma 17-hydroxyprogesterone or 17-hydroxypregnenolone may not be specific enough to categorize a woman as having lateonset congenital adrenal hyperplasia due to 21-hydroxylase deficiency or 3β-hydroxysteroid dehydrogenase deficiency. A biochemical response above a statistically defined threshold is an arbitrary screening index and should not be considered a specific phenotypic feature of disease. In. . .