[The Current Landscape of Clinical Implementation of Whole Genome Sequencing]

Whole genome sequencing (WGS) interrogates the entire approximately 3-billion-base-pair human genome and uniquely enables integrated capture of multilayered information, including variants in noncoding regions, repeat elements, complex structural variants, viral genomes, the mitochondrial genome, HLA types, and pharmacogenomic markers. Compared with comprehensive genomic profiling (CGP), which targets predefined cancer genes, WGS offers a vastly broader scope but entails substantial challenges in specimen requirements, computational infrastructure, and standardization of variant interpretation. Recent large-scale clinical studies have shown that WGS provides actionable insights that inform therapy selection and prompt diagnosis, and preparations for clinical deployment are advancing in both oncology and rare-disease medicine. Internationally, initiatives such as the UK 100,000 Genomes Project and the Netherlands' WIDE study/OncoAct® have marked key implementation milestones, while in Japan the"Action Plan for Whole Genome Analysis 2022"is establishing the framework for translation to practice and patient benefit. This review surveys WGS from technical foundations to clinical utility, global implementation, ongoing efforts and infrastructure in Japan, and remaining challenges. It sets out the case for repositioning WGS from a research tool to a patient-oriented foundational technology and outlines its potential to deliver patient benefit and accelerate drug development.