Evidence for partial 21-hydroxylase deficiency among heterozygote carriers of congenital adrenal hyperplasia.

Concentrations of 17-hydroxyprogesterone are significantly greater in heterozygous carriers of CVAH than in controls 30 and 60 minutes after an infusion of 25 units of synthetic ACTH 1-24 and 2 hours after beginning a 4-hour infusion of 50 units ACTH. The majority of carriers were clearly above the control range at these collection times. Hence, heterozygous carriers have a partial enzyme deficiency although all cannot be diagnosed based on 17-hydroxyprogesterone levels after ACTH stimulation.