Clinical utility and cost-effectiveness of BeginNGS newborn screening by genome sequencing and standard newborn screening for severe childhood genetic diseases: an adaptive, international and comparative clinical trial.

introductionIn the last 60 years, newborn bloodspot screening (NBS) has expanded as a public health intervention from a single severe childhood genetic disease (SCGD) to up to as many as 80 SCGD and testing of ~40 million newborns/year worldwide. However, the gap between current NBS and its potential to increase the efficiency, effectiveness and global equity of healthcare delivery for SCGD is large and rapidly growing. There are now effective therapeutic interventions-drugs, diets, devices and surgeries-for up to 2000 SCGD. Since almost all SCGD can be identified by bloodspot genome sequencing, it has been a longstanding goal to supplement current NBS with genome sequencing-based NBS (gNBS) for all eligible SCGD. We recently described a novel gNBS platform (named Begin Newborn Genome Sequencing (BeginNGS)) with the potential to overcome several major challenges to gNBS (cost, scalability, false positives and an unprepared healthcare workforce). A pilot clinical trial of BeginNGS for 412 SCGD in a level IV neonatal intensive care unit (NICU) had a true positive rate of 4.2%, sensitivity of 83%, positive predictive value of 100% and clinical utility rate of 4.2%, indicating readiness of the platform for use in a powered, multicentre study. METHODS AND ANALYSIS: The BeginNGS study is a single group, international, multicentre, adaptive clinical trial to compare utility, acceptability, feasibility and cost-effectiveness of BeginNGS gNBS (experimental intervention) with standard NBS (control). A minimum of 10 000 neonates (aged <28 days, maximum of 100 000) will be enrolled across 25 racial, ethnic and ancestry populations and five enrolment site types (high-risk obstetrician offices, labour induction office visits, newborn nurseries, NICUs and well-baby visits). BeginNGS is gNBS for circa 2000 SCGD (currently 508 SCGD). The primary objective of the trial is to generate equitable evidence to support broad implementation of gNBS. Enrolled newborns receive both interventions (BeginNGS and standard of care NBS). Newborns who screen positive receive confirmatory testing and medical follow-up for at least 1 year to obtain outcomes data. The primary outcome measure is clinical utility, defined as the proportion of diagnoses identified by BeginNGS and state NBS during infancy that are likely to benefit (likely to have an improved outcome) from treatment. We hypothesise that BeginNGS has a greater rate of clinical utility than standard NBS. An adaptive design was chosen rather than a traditional, fixed design to allow accumulating results to make the trial more efficient, informative, equitable and ethical by addition or removal of SCGD and genetic variants, population enrichment (for under-represented racial, ethnic and ancestral groups) and sample size re-estimation. Adaptive design will also facilitate meta-analysis with other clinical trials of gNBS, providing greater power to test utility in ultra-rare SCGD. Parents will be approached (in person, via phone or via electronic communication) to provide informed consent to enrol their newborns prenatally, postnatally in newborn nurseries or NICUs or at well baby outpatient visits. This study is part of phase III of the BeginNGS programme. Patient and public voices have been engaged in the design and execution of each BeginNGS phase through individuals and groups joining the BeginNGS consortium and participating in the family and community engagement work group. gNBS has the potential to transform the way we diagnose and treat childhood genetic diseases. Preliminary data suggest that national adoption of BeginNGS for all births has the potential to improve outcomes of >50 000 US children per year. ETHICS AND DISSEMINATION: This study was approved by the WCG Clinical institutional review board on 14 February 2024, and the most recent amendment approved on 7 October 2025 (approval number 20235517). Study findings will be shared through research consortium workshops, national and international conferences, community presentations and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT06306521.