Should we sequence everyone’s genome? No

This is an exciting time to work in medicine. The enormous advances in our understanding of inherited diseases that have flowed from sequencing the human genome mean that many patients benefit from faster, more accurate diagnoses, targeted screening, cascade testing for relatives, and the availability of prenatal diagnosis and pre-implantation genetic diagnosis. Clinicians see patients, take a family history, examine them, and then decide which tests will confirm or exclude specific diagnoses.

Sequencing the first human genome took 13 years and cost $3bn (£2bn; €2.3bn); today we can sequence a complete human genome in a few days for a few thousand pounds. The price will fall further; however, the cost and challenges of analysing, interpreting, and storing the data are substantial.1 2

Mutation screening within a single gene is rapidly being replaced by targeted screening of a relevant panel of genes known to be implicated in particular phenotypes, and whole exome or whole genome sequencing is likely to become the preferred approach in these situations over the next few years.3 Sequencing data can be filtered so that only variants in relevant genes are analysed; variants that might cause disease can then be validated by functional studies before their pathogenicity is confirmed. …