Impaired mineralocorticoid hormone responses to adrenocorticotropin stimulation: additional characterization of heterozygosity for the 21-hydroxylase deficiency type of congenital adrenal hyperplasia.

In 12 obligate heterozygotes for the simple virilizing form of congenital adrenal hyperplasia (21-hydroxylase deficiency), basal and ACTH-stimulated levels of aldosterone, corticosterone, deoxycorticosterone, 18-hydroxycorticosterone, and 18-hydroxydeoxycorticosterone were examined. The responses to ACTH were significantly impaired (P less than 0.025 less than 0.001) compared with those of normal subjects. In addition to the often exaggerated stimulation by ACTH of the immediate precursor to 21-hydroxylation, 17 alpha-hydroxyprogesterone, the heterozygotes can now be characterized further by the impaired ACTH responses of mineralocorticoids distal to the block in the zona fasciculata; the ACTH-stimulated 17 alpha-hydroxyprogesterone/18-hydroxydeoxycorticosterone ratio was greater than normal in 94% of the heterozygotes. A limitation of 21-hydroxylation may also exist in the zona glomerulosa.