The next wave of diagnostics that can scan a patient’s DNA for a host of genetic diseases needs to be better regulated to ensure the tests deliver what they promise, according to the FDA. Those regulators’ struggle to exert oversight could inform upcoming legislation to give the FDA even more authority.

Next-generation sequencing can screen millions of DNA changes in a single test, unlike traditional diagnostics that link one test to one disease. These powerful genomic tests are the linchpin...