Nationwide newborn screening for mucopolysaccharidoses in Taiwan: Impact, early diagnosis, and clinical advances over the past decade.

Abstract

Taiwan launched a nationwide newborn screening (NBS) program for mucopolysaccharidoses (MPS) in August 2015. This study evaluated the diagnostic yield, timing of diagnosis, and downstream clinical management outcomes of this population-based NBS program. As of March 31, 2025, over 838,585 infants were screened for MPS I, MPS II, MPS IVA, and MPS VI. First-tier screening was based on enzyme activity measurement from dried blood spots using liquid chromatography-tandem mass spectrometry. Screen-positive infants underwent comprehensive confirmatory evaluation, including quantitative urinary glycosaminoglycan analysis by liquid chromatography-tandem mass spectrometry, leukocyte enzyme assays, and molecular genetic testing using Sanger sequencing or next-generation sequencing. A total of 838,585 infants were screened for MPS I, 727,684 for MPS II (including 378,555 males), 351,917 for MPS IVA, and 587,158 for MPS VI. Among 437 infants referred for confirmatory testing, 7 were diagnosed with MPS I, 14 with MPS II, and 10 with MPS IVA. The corresponding prevalence rates were 0.83, 1.92 (3.77 per 100,000 male live births), and 2.84 per 100,000 live births, respectively. All confirmed cases were asymptomatic at the time of diagnosis. Implementation of the nationwide NBS program was associated with a reduction in the average age at diagnosis from 4.3 years to 0.2 years and facilitated timely initiation of disease-specific interventions, including enzyme replacement therapy and hematopoietic stem cell transplantation. In addition, the program facilitated the identification of novel MPS-related variants in the Taiwanese population, contributing to improved diagnostic interpretation and long-term disease monitoring. These findings support the clinical utility of NBS for rare lysosomal storage disorders and provide evidence to inform the development of similar programs in other regions.