Blood-spot 17-hydroxyprogesterone in nonclassical 21-hydroxylase deficiency.

The value of blood-spot 17-hydroxyprogesterone (17-OHP) measurements in selective screening for non-classical 21-hydroxylase deficiency (NC 21-OHD) among female patients with postnatal virilization was studied. Early morning basal blood-spot and serum samples, and post-ACTH serum samples for 17-OHP measurement were collected from twenty-seven patients with precocious pubarche, hirsutism and/or menstrual abnormalities (age: 3 to 17 years). Using a two-step extraction method for blood-spot 17-OHP measurements of all the nine patients with NC 21-OHD showed higher values than the eighteen patients without 21-OHD. Blood-spot 17-OHP values of patients with NC 21-OHD showed a diurnal rhythm with pathological high levels between 0500 and 0900 h, and normal or slightly elevated levels between 1700 and 2100 h. In conclusion, early morning blood-spot 17-OHP measurement is a useful method to detect NC 21-OHD in the peripubertal period.