Evaluation of 21-deoxycortisol as a marker for the detection of heterozygous carriers of 21-hydroxylase deficiency.

The study was aimed at evaluation of usefulness of determination of blood serum 21-deoxycortisol concentration for the detection of heterozygous carriers of incomplete block of 21-hydroxylase synthesis leading to adrenal hyperplasia. An earlier observation of the authors that the determination of 21-deoxycortisol is a more sensitive marker than 17-hydroxyprogesterone for diagnosing this genetic defect provided the motivation for undertaking this study. The levels of 21-deoxycortisol and 17-hydroxyprogesterone were determined in blood serum by using radioimmunoassay methods in 18 mothers and 21 fathers of children born with 21-hydroxylase deficiency, before and after intravenous administration of ACTH. As a control group served 15 women and 11 men of the corresponding age. Unlike 17-hydroxyprogesterone, 21-deoxycortisol levels were significantly higher both in women (20.5 +/- 12.6 ng/dl) and in men (21.2 +/- 14.4 ng/l) suspected of being heterozygous carriers, both before and after stimulation with ACTH, as compared to those in the control group (6.9 +/- 3.6 in women and 7.9 +/- 2.8 in men). Only in three women and in two men suspected of carrying the defective gene the values of 21-deoxycortisol were in normal range. The results obtained demonstrated evidently that 21-deoxycortisol can be regarded as a more sensitive marker for the detection of heterozygous carriers of 21-hydroxylase deficiency than 17-hydroxyprogesterone and the determination of 21-deoxycortisol is more useful for diagnosing this genetic defect.