A box of 23andMe's testing kit is pictured.

In late 2014, the Google-backed company 23andMe announced that it would start selling its direct-to-consumer (DTC) genetic test in Canada and the UK — despite being banned by the US Food and Drug Administration (FDA) from selling it in the United States following misleading marketing.

The genetic test provides information for around 108 health conditions for which some degree of evidence exists, including 44 inherited conditions, 12 drug responses, 12 genetic risk factors and 41 traits. Some conditions on the list are both obvious and innocuous. For example, hair colour, eye colour, and height are among the 41 traits. But many of the results are about important health conditions, and are clearly supposed to incite a change in behaviour.

Genetic testing is appropriate — and can be life saving — when doctors and genetic counsellors interpret complex results and map out the various courses of action. However, DTC genetic testing companies, such as 23andME, deliberately eschew the framework between clinician and patient. Under the banner of personal empowerment, DTC companies proclaim that their products confer a new level of control over one’s health, and that...