[Neonatal mass-screening for congenital adrenal hyperplasia due to 21-hydroxylase deficiency. II. A pilot neonatal mass-screening study in the west of Shizuoka Prefecture, Japan].

Using a simplified radioimmunoassay method for "Disc-17 alpha-hydroxyprogesterone (Disc-17-OHP)", a pilot neonatal mass-screening study for 21-hydroxylase deficiency was performed in the West of Shizuoka Prefecture for a period of 19 months. During this period, 20,975 neonates were studied, and the mean value and S.D. of "Disc-17-OHP" values were 21.1 and 9.65 pg/disc, respectively. We tentatively decided the 99th-percentile value as a recalling point, and 219 neonates (1.04%) were the candidates for recall by this criteria. One hundred thirty-six neonates out of these 219 candidates who responded to recall were evaluated by physical examination, family history and measurements of plasma electrolytes, 17-OHP and 21-deoxycortisol values as well as concentrations of pregnanetriol and pregnanetriolone in spot urine specimens. As a result, 2 infants were proved to have the salt-losing type of 21-hydroxylase deficiency (21-OHD). Approximately one half of the candidates were premature or low birth-weight infants, and at least 80% had a history of some kind of problem at delivery or in the early neonatal period. Despite the problems remaining to be solved, the present study demonstrates the feasibility and importance of neonatal mass-screening programs for 21-OHD, and suggests that the incidence of 21-OHD is probably greater than previously expected.