Congenital adrenal hyperplasia due to combined 21- and 11 beta-hydroxylase deficiency.

A 26-day-old male was evaluated because on routine follow-up visit his weight was noted to be 3292 g which was not a significant weight gain over his birth weight of 3178 g. His serum electrolytes (NA 107 meq/1, K 8.0 meq/1, Cl 82 meq/1, and HCO2 12 meq/1) were abnormal, urine Na concentration (68 meq/1) was high, and his serum concentrations of 21-deoxycortisol 10, 113 ng/dl (normal 1.2-13), 11-deoxycortisol 15,000 ng/dl (normal 50-250), and 11-deoxycorticosterone 148 ng/dl (normal 2-13) were markedly elevated. Patients having increased levels of the three indicated steroids are diagnosed as having combined 21- and 11 beta-hydroxylase deficiency. On glucocorticoid and mineralocorticoid replacement therapy his electrolytes returned to normal and his weight increased 428 g by the 10th day post initiation of therapy. We hypothesize that the elevated steroid pattern designated as combined 21- and 11 beta-hydroxylase deficiency could result from extraadrenal conversion of 17-hydroprogesterone to 11-deoxycortisol and progesterone to 11-deoxycorticosterone in subjects with adrenal 21-hydroxylase deficiency.