A pilot study on newborn screening for congenital adrenal hyperplasia in Beijing

Background: A provisionary screening programme for 21-hydroxylase deficiency (21-OHD) was initiated in Beijing in 2014. The aim of this study was to investigate the incidence and the associated clinical characteristics of neonatal congenital adrenal hyperplasia (CAM) in Beijing and to provide evidence-based guidance for its application in CAH screening. Methods: Live birth newborns (n=44,360) were screened for CAH in Beijing from July 2014 to April 2018. The levels of 17-hydroxyprogesterone (17-OHP) in the blood were estimated using the time-resolved fluoroimmunoassay. Neonates with a positive result and a level >30 nmol/L of 17-OHP were called for a retest. CAH was diagnosed based on further laboratory findings combined with clinical signs, such as weight loss, feeding difficulties, skin pigmentation, and atypical genitalia. Through a review of medical records, the clinical findings including molecular data were reported. Results: Of the 44,360 neonates screened, 280 cases were deemed positive. Of these, 203 neonates were recalled for further tests and six patients (three boys and three girls) were diagnosed with CAH. Five cases of classic salt-wasting and one case of simple virilising 21-OHD were identified. The incidence of CAH in Beijing was 1:7393. The most frequent 21-OHD mutation was c.293-13C/A > G. Conclusions: The incidence of CAH in Beijing was higher than the national average. The results support the need for neonatal CAH screening in Beijing. This pilot study demonstrates the clinical characteristics of 21-OHD through newborn screening. Early detection and treatment through neonatal screening may reduce mortality rates and optimise developmental outcomes.