From PKU to Genome Sequencing: The Past, Present, and Future of Newborn Screening

BACKGROUND: Newborn screening (NBS) is a foundational public health program designed to identify severe but treatable conditions in presymptomatic newborns. Since Robert Guthrie introduced the phenylketonuria test in the 1960s, NBS has evolved from single-condition assays to multiplex platforms, enabling early diagnosis, intervention, and long-term follow-up. Understanding the historical, technological, and organizational aspects of NBS is critical to addressing the challenges posed by the integration of genomic technologies. CONTENT: Tandem mass spectrometry forms the backbone of current NBS, allowing cost-effective detection of multiple metabolites and expanding the scope of screening. NBS requires coordinated efforts among primary care providers, specialized teams, and state public health programs. Although the federal Recommended Uniform Screening Panel currently includes 64 conditions, adoption and implementation vary across states. Advances in genomic technologies, particularly next-generation sequencing (NGS), offer the potential to further expand NBS, complementing rather than replacing traditional functional screening. Integrating NGS raises challenges, including selection of disorders, management of variants of uncertain significance, presymptomatic diagnoses, and ethical and privacy considerations. Evidence is still needed to define the clinical utility, cost-effectiveness, and long-term outcomes of population-wide genomic screening. SUMMARY: NBS has transformed over the past 6 decades from single-condition testing to complex, multi-disorder programs. While genomic technologies promise further expansion, careful evaluation of clinical, ethical, and practical considerations is essential to ensure that NBS continues to provide timely, equitable, and beneficial care to all newborns.