Interpretation of an ACTH stimulation test in a prepubertal child with premature pubarche

ACTH: adrenocorticotropic hormone (cosyntropin); CAH: congenital adrenal hyperplasia; 17OHP: 17-hydroxyprogesterone; DHEAS: dehydroepiandrosterone sulfate; HSD3B2: 3-beta-hydroxysteroid dehydrogenase type 2 gene; CYP11B1: steroid 11-beta hydroxylase gene.
* 17OHP >1000 ng/dL after ACTH stimulation is diagnostic of CAH due to 21-hydroxylase deficiency. Intermediate values (eg, 335 to 1000 ng/dL) usually indicate a carrier state for 21-hydroxylase deficiency or another type of CAH but occasionally is seen in normal individuals. Molecular genetic testing is suggested to confirm the diagnosis. Children with classic CAH (both salt-losing and simple-virilizing forms) typically develop virilizing signs and symptoms prior to 4 years of age if untreated. Children with nonclassic CAH typically present after age 4 years with premature pubarche or during adolescence with hirsutism and irregular menses.
¶ 17OHP levels post-ACTH between 335 and <1000 ng/dL are compatible with the carrier state for 21-hydroxylase deficiency or inactivating mutations of HSD3B2 or CYP11B1. Refer to UpToDate content on uncommon forms of CAH.