Spit decisions: DIY tests endanger DNA data



When One Nation puts forward a policy to DNA test Aboriginal and Torres Strait Islander people, DNA databases are solving crimes abroad, and commercial ancestry kits are as popular as ever, it's important to ask what we're giving away when we get our DNA sequenced.

Chris Johnston cartoon shows a person in a coat shedding colourful ribbons designed to look like DNA strands. The ribbons are studied by a doctor, who then passes them on to a government agent.Although direct to consumer DNA tests might seem like a harmless way to connect with lost relatives and find out about your ancestry, you'll only ever have one set of genes and once that data is out there it's very hard to get it back.

As the cost of sequencing the human genome has rapidly fallen, DNA services such as 23andMe and Ancestry have quickly risen in popularity, allowing easy access to your genome with just a bit of saliva in a tube.

These companies usually offer two things: to identify specific gene markers which give you details about your health (such as the gene for celiac disease or lactose intolerance), and to match your DNA to a database which compares it to DNA of other people of a known ancestry. The tests are not always accurate in either case, and any information gained from them should be taken with a grain of salt.

But that's just the start of your problems. Once your DNA is sequenced and you get the results, that data doesn't remain with the provider of the tests. Many of these companies sell the de-identified data to drugmakers and scientists, and it's difficult to later delete the results off your account (although it can be done in certain circumstances). Many providers also have the right to keep your saliva frozen for many years after the test. 

Even if you've never taken a DNA test you could still be at risk, as your actual DNA doesn't need to be in a database for you to be identified — if a family member has done a test, you're out of luck. A study late last year found that white Americans have a 60 per cent chance that a relative has added their DNA to a database — which is then able to be used to identify them. 

Between 2007 and 2017 it's estimated that 12 million people took a consumer DNA test. But 7 million of those people took the test in 2017. This has only expanded in the last two years — when I contacted 23andMe they explained they have sold 10 million kits to date.


"Until governments, geneticists and other industry experts manage to have that conversation in Australia, maybe think twice before spitting into any tubes."


Not every country has fallen in love with these tests. Germany and France have pretty much banned direct to consumer DNA testing, instead requiring that the patients speak to a genetics specialist and undergo any tests through them.

In Australia, experts argue that the government has been too slow to keep up with any ramifications of DNA testing. Life insurance providers can discriminate on the basis of your DNA results, but a recent law change means you don't always have to tell the provider if the result is unfavourable.

The results you get from these DNA tests — especially for minority Australians — are also likely incorrect. There's been numerous cases of Aboriginal Australians being inaccurately classed as having no Aboriginal ancestry

Unfortunately DNA testing is not going away, even ignoring commercial DNA kits. In the next few years, having a DNA test done by a doctor could become routine — helping you make better informed decisions about your health long before you're sick. When this happens, the same issues with medical information on My Health Record will again come into play. It's important that our general medical records are kept private and secure, and with our DNA data this is even more vital.

But until governments, geneticists and other industry experts manage to have that conversation in Australia, maybe think twice before spitting into any tubes.



Jacinta BowlerJacinta Bowler is a science journalist and fact checker living in Melbourne.

Topic tags: Jacinta Bowler, DNA testing



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Existing comments

This is a little bit like the SBS TV series "Every Family Has A Secret". I have watched it, fascinated. Yet I can not see the attraction of finding out. The perversity of I'm not sure what.
Pam | 01 July 2019

It is a rather serious matter if the results of DNA testing can be anything but factual. The author is light on facts. If numerous known Aboriginal people have been tested and found not to be Aboriginal then it suggests the process is akin to a tarot card reading, whereas DNA testing is refuted to be a scientific process. Just how can this be?
John Whitehead | 01 July 2019

What negative DNA testing for aboriginality (or any other trait) means, John Whitehead, is that some who claim to be aboriginal are in fact not aboriginal. As you intimate in your comment the science is valid. There are many instances of DNA testing indicating that some people are not what/who they claim to be - usually where money or personal advantage is involved eg inheritance, parenthood etc and dare I say it , benefit attributed to race.
john frawley | 01 July 2019

Re comments on Aboriginality: my understanding is that the results of some DNA tests - Ancestry, for example - are calculated on the numbers of people with similar genetic profiles to that of the test subject, and where they live. For example, my result showed that I’m 97% Irish, from Ulster. I’ve never been in Ireland, my father is English as far back as we can trace, my mother’s parents we’re from Eire - but most people with a similar profile to mine live in Northern Ireland. It seems that when Aboriginal people have been wrongly classified as having no Aboriginal ancestry, it’s because there are not enough Aboriginal people with similar profiles living in any one place. This has to do with the comparatively small numbers of Aboriginal people in any one area, and the fact that the majority of their DNA came through non-Aboriginal ancestors. It certainly does not mean that they are not Aboriginal at all. This is one of those cases where we need to understand exactly what the science is measuring.
Joan Seymour | 02 July 2019

One of the most chronic bores I know keeps raving on about his family history and the results of his DNA test. When I see him again I will remember your article and smile inwardly.
Edward Fido | 05 July 2019

Thanks Joan, you make clear how fraught the interpretation of these genetic "tests " really is. But you also make clear that other commentators don't understand what they are saying. Social media pundits, please refrain from voicing your unhelpful and misleading opinions about matters of probability requiring informed scientific interpretation. Genetic test sellers should be required to provide standard measures of test reliability and validity, and account for sampling ,interpretation and other biases. They should also reveal their privacy conditions and their commercial data trading partners.
jpb | 07 July 2019


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