A neonatal mass-screening for congenital adrenal hyperplasia in Japan.

A pilot neonatal mass-screening for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) was performed in the western region of Shizuoka Prefecture, Japan, using a simplified radioimmunoassay method for 'Disc-17-hydroxyprogesterone (17-OHP) determination. The results obtained during a 30-month period indicated that 3 infants out of the 34314 neonates examined were proved to have 21-OHD, and the incidence of homozygotes and heterozygotes were estimated to be 1:11438 and 1:54, respectively. At the time of recall, the concentrations of plasma 17-OHP and 21-deoxycortisol and their urine metabolites as well as plasma sodium levels were quite applicable to diagnosis, while the clinical signs that may be manifest in 21-OHD were of little value in this connection. Prematurity and perinatal complications of neonates tended to give false-positive results, being secondary to the function of the residual foetal adrenal cortex and non-specific stimulatory effects of various stresses. Despite several technical and practical problems to be solved, the present study demonstrated the importance and validity of a neonatal mass-screening program for CAH.