Five things to consider before ordering an online DNA test

You might be intrigued by what your genes could tell you about your ancestry or the health risks hidden in your DNA. If so, you’re not alone.

Fascination with personal genetics is fuelling an explosion of online DNA testing. More than 12 million people have been tested – 7 million through ancestry.com alone. Amazon reported the 23andMe online DNA test kit as one of its top five best-selling items on Black Friday in 2017.

But while online genetic testing can be interesting and fun, it has risks. Here are five things to keep in mind if you’re considering spitting in a tube.

1. Understand the limits of what’s possible

Keep in mind the evidence behind claims a DNA testing company makes. Some companies list the science that backs up their claims, but many don’t.

DNA testing can be used to tell your ancestry and family relatedness quite accurately, but companies claiming to predict wine preferences or children’s soccer prowess from DNA are in the realm of fantasy.

There is also a lack of regulation on this issue to protect consumers.

2. Make sure you’re prepared for the information

Genetics can tell us many things, some of which we may not be prepared for. You may go in looking for information on your ancestry, but could find out about unexpected paternity. Or you might discover you’re at risk of certain diseases. Some of these have no cure, like Alzheimer’s disease, which could only leave you distressed.

Read more: Genetic testing isn't a crystal ball for your health

Some products can test for genetic changes in the BRCA genes that put you at risk of breast and ovarian cancers. Other online genetic interpretation tools can take raw data from ancestry DNA tests and, for a small payment, provide a wide range of disease risk estimates, many of which have been brought into question by the scientific community.

Think carefully about whether you really want to know all this information, and whether it’s valid, before you proceed.

3. Consider the medical follow-up you might need

If something serious is discovered in your genes, you might need the results to be professionally interpreted, or to have genetic counselling to come to terms with what you’ve learnt.

Some genetic information can be complex and difficult to interpret, and have medical implications for you and your family. Relying on the internet for interpretation is not advised.

Read more: A little bit of knowledge: the perils of genetic tests for Alzheimer's disease

Does the DNA testing company offer any counselling or medical services? If not, are you hoping your GP or genetics clinic will provide this? You might find GPs are not adequately trained to understand DNA results, and public genetics services have very long waiting lists. This means you might be left on tenterhooks with a potentially distressing result.

4. Think how the results may affect your insurance

In Australia, private health insurance can’t be influenced by genetic test results. But life insurance companies can use genetic test results to discriminate against applicants, with little consumer protection. All genetic test results known to an applicant at the time of a life insurance application must be disclosed if requested, including internet-based test results.

Read more: Australians can be denied life insurance based on genetic test results, and there is little protection

Once you have a result that indicates increased risk of disease, the life insurance company may use this against you (by increasing premiums, for instance), even if the scientific evidence isn’t solid. This applies to life, income protection, disability and even travel insurance.

5. Consider who will have access to your DNA and data

Some online genetic testing companies don’t comply with international guidelines on privacy, confidentiality and use of genetic data. Many online testing companies retain DNA samples indefinitely. Consumers can request samples be destroyed, but sometimes have difficulties with this.

Some online testing companies have been accused of selling access to databases of genetic information to third parties, potentially without the knowledge of donors. You might have to plough through the fine print to find out what you have consented to.

Read more: Take an online DNA test and you could be revealing far more than you realise

In many ways, it is wonderful we now have access to our personal DNA code. However, as always, understanding the limitations and risks of fast-moving medical technology is very important.

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.