SERUM ANDROGEN CONCENTRATIONS IN NEONATES AND YOUNG INFANTS WITH CONGENITAL ADRENAL HYPERPLASIA DUE TO 21‐HYDROXYLASE DEFICIENCY*

Abstract

SUMMARYConcentrations of androstenedione (Δ4‐A), dehydroepiandrosterone (DHA), testosterone (T), and 17‐hydroxyprogesterone (17‐OHP) were measured in cord sera and in sera of normal and sick infants from birth to 18 months of age, and were compared with those of five male and five female infants with congenital adrenal hyperplasia due to 21‐hydroxylase deficiency (CAH). Cord blood androgen concentrations (Δ4‐A, DHA, T) in three affected CAH newborns and 17‐OHP in two of these infants did not differ from those of normal newborns (twenty females, thirty‐four males). Postnatally, in infants with CAH, both Δ4‐A and 17‐OHP was highly elevated while DHA was not different from that of normal or sick infants. However, one very sick infant with both elevated Δ4‐A and 17‐OHP was ultimately proven to be normal. T in all affected CAH females (70–650 ng/dl) was clearly elevated compared to normal and sick infants (<5–38 ng/dl). T concentrations in four of the five male infants with CAH (60–295 ng/dl) were indistinguishable from the T concentrations in normal newborn males (25–458 ng/dl). Following treatment, longitudinal studies of 17‐OHP and androgens in these infants with CAH showed significantly positive correlation between 17‐OHP and Δ4‐A in both male (r = 0.74) and female (r = 0.8) infants while a positive correlation between 17‐OHP and T was present only in female infants (r=0–97). Thus, serum Δ4‐A was as useful as 17‐OHP for both diagnosis and therapeutic monitoring of CAH in both sexes while T was useful only in female infants. Of interest was that T in the male infants with CAH rapidly decreased with glucocorticoid administration and remained low (< 2–11 ng/dl) for 3–4 weeks during the period when T is normally high. This suggests that in CAH the T was adrenal in origin and that testicular T was suppressed in the untreated state. These data support the presence of a negative feedback effect by excess adrenal sex steroids o n the hypothalamic‐pituitary‐gonadal axis in young male infants with CAH.