23andMe: What happens when a hypochondriac takes an online DNA test

I’m a hypochondriac – about twice a month, I convince myself I have some obscure cancer – so 23andMe’s genetic testing appeals to my internal weaknesses. Spit in a tube, mail it away, and get a detailed report of everything that’s wrong with me – not, as it would turn out, cancer, but we’ll get to that.

First, a bit about the Google-backed 23andMe. For £125, the US-based genetics company promises to reveal inherited risk factors, genetic traits, and how your body may respond to certain drugs. Sign up, and it will send a small kit in the mail with instructions to follow: spit a few times in the plastic test tube, attach a lid containing a liquid, shake it all about, pop it back in the mail.

Several weeks later, an email lands with a link to your results, which include ancestry composition and genetic traits reports. No-one, including myself, cares that I am predisposed to “wet” earwax or am 69.5% Eastern European –  it’s the medical markers we’re shelling out £125 to see.

Those detailed, wordy medical reports are at the heart of regulatory concerns about 23andMe: the US Food and Drug Administration (FDA) shut down its medical testing in 2013. It was allowed to return last year, but with fewer than a sixth of the 240 medical markers it tested for at launch. It now focuses on genetic disorders you could pass on to your children rather than the diseases you might develop in your own life. The UK version has more medical results, including 11 markers for the latter, with notes on the bottom of the results saying they’re not approved by the FDA.

The concerns centre on whether such tests can be truly predictive for diseases you may develop in life, whether average individuals can understand them, whether such tests will lead to a high number of false positives (as they’d normally be run only by professionals following symptoms) and – particularly in the US, with its paid-for health care – whether genetic information could be used to discriminate.

Concerns around communicating the results are no surprise: the reports could reveal you’re at risk of serious disease or of passing down an illness to your children – potentially life-changing information.

With all that in mind, 23andMe did a “significant amount of user-comprehension testing” as part of its FDA clearance to market, Angela Wonson, 23andMe’s vice president of communications, told me. “The threshold of user testing has to show over 90% comprehension rates, and [this is] very thorough testing of individuals who are not customers,” she said, explaining the FDA requires the results to be understood by a wide audience, not just those interested in the product.

The thing is, I thought I understood my own results – but a chat with a geneticist showed I didn’t.