The FDA’s 23andMe decision will also change the rules for all at-home medical genetic testing

Doctors are losing their role as the gatekeeper of our health information, for better or worse.

Last week, the US Food and Drug Administration made a surprise announcement giving genetic testing company 23andMe clearance to sell a service that gives customers a risk analysis for 10 genetically linked diseases. It reverses a 2013 decision that cited concerns that inaccurate testing results—and potential customer misinterpretation—made for a public health threat, and builds on a 2015 agreement between the FDA and 23andMe that allowed the company to offer a test that told customers of their “carrier status” of genetic markers for certain diseases—but not assess their actual risk. This latest decision means 23andMe will again be able to provide specific risk analyses to customers, and perhaps more importantly, throws the door wide open to dozens of other companies to run out their own versions of at-home genetic risk-analysis products.

The disease risk that 23andMe offers isn’t a diagnosis; it just gives you your potential for elevated risk. For example, if a person inherited a copy of the ApoE4 gene variant from both...