BETHESDA, July 2 -- Somewhere inside a single federal database now sits the whole genetic code and years of medical history belonging to more than 747,000 Americans, nearly half of them from communities that biomedical research has historically overlooked. On Tuesday, the National Institutes of Health said that pool of information had become the largest integrated genomic and health-record system on Earth, a milestone ten years and one act of Congress in the making.

NIH Director Jay Bhattacharya called the resource, known as the All of Us Research Program, "a national treasure," arguing that the paradox of precision medicine is that treating individuals actually requires very large populations to expose the patterns connecting genetics, ...