No evidence of an increase in early infant mortality from congenital adrenal hyperplasia in the absence of screening

Objective Congenital adrenal hyperplasia (CAN) is not currently included in the UK newborn screening programme. We investigated the hypothesis that, owing to non-specificity of symptoms, a proportion of males affected by salt-wasting (SW) CAN have died in infancy without being diagnosed. Design Stored newborn screening blood spot samples were analysed for 17 alpha-hydroxprogesterone (17-OHP) in the following groups: Infants born in the North West of England, 1994 to 2006, who had died by 6 months age; (n=1198), a neonatal reference group (full-term n=100; preterm n=100) and a CAN positive control group. A newborn blood spot sample collected before diagnosis was available in 29/61 CAN patients recruited. SW CAN was present in 18/29 patients (16 males and 2 females). Samples from the deceased group with elevated 17-OHP were analysed for 8 common mutations in the 21-hydroxylase gene (CYP21A2). Setting North West of England. Results Grouped by gestational age, mean (maximum) blood spot 17-OHP in nmol/L was as follows. Deceased full-term n=279, 6 (107); deceased premature n=365, 28 (251); deceased unknown gestational age n=553, 13 (>394). In the SW positive control group, the lowest level of 17-OHP was 179 nmol/L and 14 had levels greater than the highest standard (>268 to >420 nmol/L). All samples from the deceased group with 17-OHP results >179 nmol/L (n=6) and a further 13 samples underwent mutation analysis. No mutations were identified. Conclusions Our findings do not support the hypothesis that, in our unscreened population, males affected by SW CAN are dying prior to diagnosis.