Serum 21-Deoxycortisol, 17-Hydroxyprogesterone, and 11-Deoxycortisol in Classic Congenital Adrenal Hyperplasia: Clinical and Hormonal Correlations and Identification of Patients with 11β-Hydroxylase Deficiency among a Large Group with Alleged 21-Hydroxylase Deficiency

Introduction: 21-Hydroxylase deficiency (21OHD) is the most common cause of congenital adrenal hyperplasia, followed in frequency by 11β-hydroxylase deficiency (11βOHD). Although the relative frequency of 11βOHD is reported as between 3 and 5% of the cases, these numbers may have been somewhat underestimated. Materials and Methods: In 133 patients (89 females/44 males; 10 d-20.9 yr) with alleged classic 21OHD and five (three females/two males; 7.3–21 yr) with documented 11βOHD, we measured serum 21-deoxycortisol (21DF), 17-hydroxyprogesterone (17OHP), and 11-deoxycortisol (S), 48 h after glucocorticoid withdrawal. We also studied 20 sex- and age-matched control subjects. Serum steroid levels were determined by RIA after HPLC purification. Objectives: The objectives of this study were to: 1) quantify 21DF in patients with congenital adrenal hyperplasia, 2) correlate hormonal with clinical data, and 3) identify possible misdiagnosed patients with 11βOHD among those with 21OHD. Results: In 21OHD, 17OHP (217–100,472 ng/dl) and 21DF (