[Neonatal Screening for Congenital Adrenal Hyperplasia in Russia: A Decade of Outcomes (2015-2025) and Lessons from Clinical Cases].

Neonatal screening for congenital adrenal hyperplasia (CAH) has been conducted in Russia since 2006. An analysis of results from 2015-2025, covering 15,546,274 newborns, identified 1,871 children with classic forms of 21-hydroxylase deficiency. The average detection rate was 1:8,309 (0.012% or 1,20 per 10 000 per year) with annual variations ranging from 1.03 to 1.48 per 10,000 newborns per year. Significant interregional variability in incidence was observed, with the highest rates recorded in the Karachay-Cherkess Republic (6.16/10,000 per year), Leningrad Oblast (4.04/10,000 per year), and Primorsky Krai (3.07/10,000 per year). Among federal districts, the Urals Federal District ranked highest. The timing of diagnosis leads to critical differences in outcomes, including the risk for adrenal crisis. Newborn screening confirms its high efficiency, and the identified regional variations underscore the need for further population genetic studies to optimize medical genetic counseling.