The First-Year Outcomes of the Nationwide Neonatal CAH Screening in Türkiye: High Rate of False Positives for 21-Hydroxylase Deficiency and a Higher Detection Rate of Non-Classical Cases


GURAN T., Yuruker E., ANIK A., Atar M., çamtosun e., Eviz E., ...Daha Fazla

Journal of Clinical Research in Pediatric Endocrinology, cilt.17, sa.4, ss.488-493, 2025 (SCI-Expanded, Scopus, TRDizin) identifier identifier

Özet

Objective: Neonatal screening for congenital adrenal hyperplasia (CAH) was implemented nationwide in Türkiye in 2022. The performance of this screening program in its first year was assessed. Methods: This retrospective, descriptive study included neonates born in Türkiye between January 1 and December 31, 2022, with gestational age ≥32 weeks and birth weight ≥1500 grams. The screening protocol used a two-tier approach. In the first step, 17α-hydroxyprogesterone (17-OHP) levels were measured using fluoroimmunoassay (FIA) in dried blood spots (DBS) collected at 3-5 days of life. In-fants with positive results underwent second-tier testing using liquid chromatography-tandem mass spectrometry to measure 17-OHP, 21-deoxycortisol (21-DF), cortisol (F), and 11-deoxycortisol (S) in DBS. Those with a steroid ratio (21-DF+17-OHP)/F ≥1 were referred to pediatric endocrinology clinics for diagnostic evaluation. Results: Of 1,096,069 neonates screened (including 149,652 refugees), second-tier tests were performed on 70,455 (6.88%) infants, and 3,429 (0.27%) were referred to clinics, resulting in 91 con-firmed cases of classical 21-hydroxylase deficiency (21-OHD) CAH (77; salt-wasting, 14; simple virilizing). Twenty-two patients were diagnosed with non-classical 21-OHD CAH. The frequency of classical 21-OHD was 1 in 12,044. The first-tier FIA-17-OHP values were below 17.5 ng/mL in 99.8% of healthy neonates with ≥36 weeks gestation or ≥2500 grams and below 50 ng/mL in those with 32-36 weeks or 1500-2500 grams. Conclusion: Neonatal CAH screening facilitates early diagnosis of 21-OHD and improved patient care. Using refined cut-offs may reduce referrals six-fold and eliminate second-tier testing for 95% of in-fants. Ongoing evaluation can enhance the efficiency and cost-effectiveness of the screening protocol.