The diagnosis of 21-hydroxylase deficiency in a prematurely born infant on the basis of the urinary steroid excretion pattern.

The urine of a 6-day-old prematurely born female infant (birth weight 1060 g) suspected of having a 21-OH-deficiency showed no steroid abnormalities on capillary GLC analysis. Using GC-MS tetrahydrocortisone (THE) and also 3 alpha, 17 alpha-dihydroxy-5 beta-pregnane-20-one (17-OH-Polone) were absent, but two androstanetriolone peaks were observed. In the urine collected on day 9 THE was absent, but a large amount of 3 alpha, 11 beta-dihydroxy-5-alpha-androstane-17-one (11-HA) was found by GC-MS to be contaminated by a small amount of 17-OH-Polone. The next urine specimen collected on the 22nd day while the child received cortisol therapeutically showed the characteristic steroid profile for the diagnosis 21-OH deficiency, large peaks of 17-OH-Polone, pregnanetriol (P3) and 11-keto-pregnanetriol (11-keto-P3). Over the next few weeks two other compounds were found to have been excreted in relatively large amounts, 3 xi, 16 xi, 17 xi, 20 xi-pregnanetetrol (16-OH-P3) and surprisingly also a 21-hydroxylated compound, namely 3 xi, 20 alpha, 21-trihydroxy-5-pregnene. These same two compounds were also found in the urine of another infant with suspected 21-OH deficiency. The urinary steroid excretion patterns characteristic for 21-OH deficiency are dependent on the maturity and age of the infant. In the prematurely born infant androstanetriolones appear in the urine before 17-OH-Polone. The occurrence of these different steroid excretion patterns is tentatively explained.