Ampliação da triagem neonatal no estado do Rio de Janeiro: estudo longitudinal dos casos suspeitos de erros inatos do metabolismo

Abstract

Introduction: Neonatal screening is a fundamental public health strategy for the early detection of inborn errors of metabolism (IEM), enabling timely interventions and preventing severe complications. In Brazil, despite the National Newborn Screening Program (PNTN), d ata on coverage, clinical profile, and the effectiveness of follow-up remain limited. Objective: To analyze the incidence of IEM included in phase 2 of the PNTN in the State of Rio de Janeiro, between March 2024 and September 2025, as well as the rates of suspected cases and false positives. Additionally, to describe the sociodemographic profile of suspected and confirmed cases and, among confirmed cases, the clinical and laboratory characteristics. Methodology: A retrospective observational study involving medical record review of infants referred due to abnormal newborn screening results for IEM and followed at the pediatric nutrition service of the Instituto de Puericultura e Pediatria Martagão Gesteira (IPPMG) between March 2024 and September 2025.Results: The final sample consisted of 115 individuals, of whom ten children had a confirmed diagnosis. Molecular testing confirmed 90% of the cases, including four cases of medium-chain acyl-CoA dehydrogenase deficiency (MCAD), three cases of glutaric acidemia type I (GA1), one case of citrullinemia type I, and one case of homocystinuria. One case of maple syrup urine disease was diagnosed based on a compatible clinical presentation and biochemical profile. Among the excluded cases, nonspecific abnormalities and elevated tyrosine levels were the most prevalent findings.Conclusion: In the present study, 90% of individuals had their IEM diagnosis confirmed during the presymptomatic phase, enabling timely treatment and preventing severe sequelae. Additionally, the findings highlight the importance of improving coverage, active case finding, laboratory infrastructure, and integration between screening centers and referral services.