[Newborn screening for congenital adrenal hyperplasia in France].

Congenital Adrenal Hyperplasia (CAH) is a genetic disorder, mostly (95%) due to CYP21A2 mutations. Its incidence in France is 1/15,000 to 1/16,000 births. The screening of newborns in France is effective since 1996, by using a 17-hydroxyprogesterone dosage on a dried blood spot. This screening allowed, as in other countries, a decrease in mortality and in morbidity by earlier management of adrenal crisis usually symptomatic from the 2nd week after birth. The French Newborn Screening has for now adopted the two-tier screens on the same dried blood spot, using a fluoroimmunoassay on both screens. This approach provides a high sensitivity, but has also a low positive predictive value. New strategies including the LC-MS/MS method can be considered in the future.