PREMATURE ADRENARCHE RESULTING FROM SYMPTOMATIC NONCLASSICAL CONGENITAL ADRENAL HYPERPLASIA

Abstract

Among 25 patients (19 girls and 6 boys) with premature adrenarche, 8 were diagnosed as having mild, asymptomatic, nonclassical 21-hydroxylase deficiency (21-OH def) based on elevated ACTH stimulated 17-hydroxyprogesterone (17-OHP) and decreased ratio of 17-hydroxypregnenolone (Δ5-17P)/17-OHP; 2 were suspected of having a partial adrenal 3β-hydroxysteroid dehydrogenase deficiency (3β-HSD def) based on high responses of Δ5-17P to ACTH stimulation and elevated ratio of Δ5-17P/17-OHP. Elevated morning Δ5-17P in a 5-year-old girl with 3β-HSD def revealed diurnal variation. In all 7 patients with suspected genetic steroidogenic defects who received dexamethasone (dex), there was prompt suppression of elevated hormone levels. The remaining 15 patients with premature adrenarche did not have abnormalities in steroidogenesis, although some androgen levels were elevated and suppressed with dex, and those were classified as idiopathic. In conclusion, we propose that premature adrenarche with excessive Δ5 and Δ4 steroid production in association with partial steroid enzyme defect is probably due to late-onset, nonclassical congenital adrenal hyperplasia, and this condition is probably more common than has been previously recognized.