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This summary covers The Economist’s July 4th, 2026 Science & technology article listed in the contents as Sequencing babies' genomes and published under the headline The genomic generation.

Sequencing a newborn’s entire genome could reveal serious illnesses before symptoms appear, when treatment has the best chance of working. It could also burden healthy children with frightening predictions that never come true and place their most intimate data at risk for life. The article argues that the technology’s medical promise is real, but the case for universal screening depends on choosing carefully what to report, how to explain uncertainty and whether diagnosis should be tied to long-term research.

Earlier answers, uncertain futures

Most newborn-screening programmes test blood for markers of a limited set of treatable conditions. Whole-genome sequencing can search much more widely. England’s Generation Study plans to sequence 100,000 babies and screen for roughly 200 childhood disorders; an American project has examined around 1,000 genes, including some associated with cancers that emerge only in adulthood.

The potential benefit is illustrated by Freddie, an English baby whose participation in the Generation Study led to an early diagnosis of retinoblastoma, a rare eye cancer. Prompt treatment greatly improved his prospects of growing up with normal vision. Similar trials in America, Australia and Europe are testing whether such screening should become routine.

The central complication is that a risky genetic variant is not a diagnosis. Geneticists use “penetrance” to describe the share of people with a mutation who actually develop the associated disease. Many estimates are based on patients who were already ill and may therefore exaggerate the danger. Mutations in the RB1 gene, for example, were once thought to cause retinoblastoma in more than 90% of carriers, but newer work found that fewer than a third of adults with risky variants had developed the cancer.

Broad screening could therefore create large numbers of “patients-in-waiting”: healthy children monitored for conditions they may never have. The consequences can extend beyond anxiety. A mutation associated with medullary thyroid cancer may lead doctors to remove a child’s thyroid, even though recent evidence suggests the mutation is less predictive than previously believed. The child would then need replacement hormones for life.

Screening is not the same as research

Programmes can reduce these harms by reporting only variants that reliably predict treatable childhood diseases and by explaining that genetic risk is not certainty. Yet many projects have a second purpose: storing participants’ genomes so researchers can study rare disorders, predict drug reactions and identify candidates for treatments developed years later. Artificial intelligence may make these databases even more useful by improving scientists’ ability to interpret genetic variation.

That value comes with exceptional privacy risks. A genome cannot be changed like a password and may expose information about disease, family relationships and future health. The 2023 theft of genetic and personal data belonging to 6.9m customers of 23andMe showed the scale of possible breaches. Genetic results may also affect insurance premiums in some countries or provide material for discrimination and blackmail.

The article’s sharpest ethical concern is “mission creep”. Some trials require parents to accept both immediate medical screening and indefinite storage of their baby’s genome for research, even though these activities rest on different justifications. Screening should benefit the child being tested; research may mainly benefit other people in the future. Newborns cannot consent to either arrangement for themselves.

Whole-genome screening could spare some children years of delayed diagnosis and prevent avoidable harm. But more information is not automatically better medicine. A responsible programme must separate actionable findings from speculative risks, keep medical care distinct from research participation and give families genuine control over data that will remain sensitive for a lifetime.