The Spanish Uniform Newborn Screening Panel (SUSP): A National Consensus Framework for Harmonized Newborn Screening

Background: Newborn screening (NBS) is a cornerstone of preventive medicine, enabling early diagnosis and treatment of severe congenital disorders. In Spain, despite the existence of a Basic Common Portfolio, the absence of a harmonized national panel has led to significant inter-regional variability, affecting equity in access to early diagnosis. Methods: The Spanish Uniform Screening Panel (SUSP) was developed through a structured nationwide consensus process involving all NBS centers in Spain, with additional input from Portugal. The process included a comprehensive survey of current practices, expert workshops, multiple consensus rounds, and predefined inclusion criteria. Disease nomenclature was standardized using OMIM and ORPHAcode identifiers. Conditions were classified as primary screening targets or secondary findings, and consensus was reached on confirmatory biochemical and genetic testing pathways. Results: The operational dataset comprised 48 biomarker-based screening entries. Because some conditions can be detected through multiple primary markers, duplicate analytical routes were retained but counted once, resulting in a total 189 unique clinical conditions, including 87 primary and 102 secondary conditions. Conclusions: The SUSP represents the first nationwide harmonized framework for newborn screening in Spain and constitutes a major step toward equitable and standardized implementation. It provides a scalable model that may inform other countries facing similar disparities.