Neonatal mass screening for congenital adrenal hyperplasia in Tokyo

Abstract Nation-wide neonatal mass screening for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) has been performed in neonates in Japan since January 1989. In Tokyo, between April 1989 and March 1991, 190,094 newborns were screened, and 12 cases of CAH were detected. There were 2 cases with the simple virilizing (SV) type, and 10 of the salt-losing (SL) type. The incidence of CAH was I in 15,841 live births, which is two- to threefold higher than previously found in case-assessment studies in this country. The ratio of the SL to the SV type was also higher than previously reported, and the patient's clinical symptoms were less marked than previously reported. The usefulness of mass screening for CAH is strongly recommended, especially for salvaging those with the severe type of 21-OHD, and detecting 'symptomatic patients with the SV type.