The Diagnosis of Nonclassic Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency Based on Serum Basal or Post-ACTH Stimulation 17-Hydroxyprogesterone Can Lead to False-Positive Diagnosis

The study investigated the accuracy of using serum 17-hydroxyprogesterone (170HP) levels to diagnose nonclassic congenital adrenal hyperplasia (NCCAH) in 40 women with hyperandrogenism. It found that relying on 170HP levels, both basal and post-ACTH stimulation, can lead to a high rate of false-positive diagnoses. Out of 21 patients with elevated 170HP levels, only 5 (24%) were confirmed to have NCCAH through additional urinary steroid profile and genetic testing. The study concluded that a definitive diagnosis of NCCAH should not be based solely on 170HP measurements but should be confirmed with more specific tests, as 170HP levels can be misleading.