Abstract
BACKGROUND: In 2001, Brazil implemented a national newborn screening (NBS) for various conditions, including phenylketonuria (PKU). Data is lacking on the effectiveness of the NBS program in diagnosing PKU at birth and initiating treatment with a Phe-free amino acid-based formula within 30 days of diagnosis. This study evaluated the effectiveness of the NBS program and characterized the PKU population. METHODS: An observational, repeated cross-sectional population-based study was conducted using anonymized data from the Department of Informatics of the Unified Health System (DATASUS) in Brazil from 2008 to 2021. Only patients with confirmed diagnoses were included. FINDINGS: NBS coverage of live births within 30 days of birth was >80% for all years, while annual incidence of PKU ranged from 4 to 8 per 100,000 live births. Median time to screening diagnosis from birth was approximately 18 days (all years). DATASUS had 7615 patients with a record of PKU. The median age of the first record in DATASUS was 6.1 years, predominantly from the southeast region (53%). Also, 44% of the PKU population had a record of receiving Phe-free formula for treatment. Metabolic and related disorders were most prevalent in those <18 years of age (28.1%), while mental and behavioral disorders were most prevalent in those ≥18 years of age (100%). INTERPRETATION: Further investigations are necessary to enhance the effectiveness of NBS coverage, reduce the time from diagnosis to treatment initiation, improve Phe-free formula distribution, and improve DATASUS data quality. FUNDING: The current study was funded by BioMarin Pharmaceutical, Novato, CA.