15-BETA-HYDROXYLATED STEROIDS MAY BE DIAGNOSTICALLY MISLEADING IN CONFIRMING CONGENITAL ADRENAL-HYPERPLASIA SUSPECTED BY A NEWBORN SCREENING-PROGRAM

In a Swiss screening programme for detection of congenital adrenal hyp erplasia (CAH), 27 of over 120,000 newborns examined from 1992 to 1994 were further studied because of persistingly high 17 alpha hydroxypro gesterone (17OHP). Out of 27, 11 were later confirmed to have CAH by s pecific gas chromatography of urinary steroids and ACTH test at age 3- 4 months. Of 27, 11 were born at term (7 confirmed 21-hydroxylase defi ciency, one 11 beta-hydroxylase deficiency). Out of 27, 16 were preter m newborns. Of them, only 2 were confirmed to have CAH (one 21-, one 1 1 beta-hydroxylase deficiency). In 3 cases with high 17OHP, but later not confirmed CAH, what appeared to be a preganaetriolone peak in the gas chromatograms was shown to be 3 beta: 15 beta, 17 alpha-pregnenetr iol. This compound may be misleading in confirming the diagnosis of CA H. LSP-Hydroxylated compounds occur in fetuses, neonates, and amniotic fluid. Since human tissues do not have 15 beta-hydroxylating capacity , their origin is unclear. However, since some bacteria (Bacillus mega therium) and mycelial fungi (fusaria) are known to hydroxylate steroid s in position 15 beta, it is likely that this compound is formed by mi cro-organisms in the enterohepatic circulation of newborns or their mo thers. Conclusion For the confirmation of the diagnosis of CAH in case s suspected by screening, later ACTH stimulation and specific steroid analysis are necessary.