What do we need to know about online genetic testing?
Tuesday, Oct 2, 2018, 05:29 AM | Source: Pursuit
Sylvia Metcalfe, Chriselle Hickerton
Unlucky in love? Perhaps you haven’t found your genetic match yet.
Or maybe you’re wondering what interests you should encourage your child to follow. DNA testing claims to offer an answer to that, too.
You can even find out what kind of wine you’re genetically predisposed to enjoy.
Personal genomic testing, offered as online DNA tests and often sold direct-to-consumer, is exploding worldwide. In Australia, it’s most widely used through genealogy websites, which market DNA testing to help you understand your ethnic make-up and discover long-lost relatives.
But there is a darker side to DIY genetic testing, with in-the-know consumers able to source reports on their predisposition to diseases like Alzheimer’s or breast cancer, without any medical advice or support.
Recently, the NextGen home test kit, which markets itself as a way to screen for serious medical conditions in babies and children, came under fire from the Royal College of Pathologists of Australasia for the test taking place “without parents having had a discussion with their doctor, prior to the test being done”.
So what do Australians think about personal genomics and what should they be wary of?
These are some of the questions the Genioz study, at the Murdoch Children’s Research Institute (MCRI) is seeking to answer. Its team of researchers from several institutes and universities have gathered the views of over 3000 Australians through focus groups, an online survey and forums.
We caught up with lead researcher Professor Sylvia Metcalfe and research assistant Chriselle Hickerton, who are both based at MCRI and the University of Melbourne, to find out more about this growing area.
Can I get a genetic health report online, without going to the doctor?
Professor Metcalfe: Traditionally, genetic testing has been done for clinical reasons, usually when someone presents with symptoms or a family history of an inherited disease, like Huntington’s disease, or some forms of breast cancer.
But now you can go online and do broader testing that looks at genetic variants throughout the entire genome - DIY genetic testing.
At the moment there are no companies based in Australia offering these tests, but some companies in Asia and Europe do and you can access them online without a doctor’s referral.
Ms Hickerton: Or people sometimes use the results from, say, an ancestry test, to then seek a separate report on their health.
They download that raw data which goes to a third-party site and they then get a health information report that comes with risk estimates for various conditions. But some interpretation is usually needed.
It’s quite complex and without support from a health professional, like a genetic counsellor, people may not understand their results, as well as any implications, and so may not act appropriately.
How reliable are DNA reports from ancestry companies?
Ms Hickerton: While they promise you can ‘discover your ethnic mix’ by submitting a sample of your DNA, their reports can be inaccurate.
Some studies show that, in some isolated populations, patterns of DNA from certain ethnic groups can be identified, but to take DNA data and report a breakdown of someone’s ethnicity, without knowing anything else about them, is spurious.
Ancestry companies like ancestry.com.au or 23andme.com use the same technology as clinical genetic tests. They base their reports on patterns in their own population databases and those databases are growing and becoming more accurate as more people complete the tests, accompanied with comprehensive family tree information.
And false results can happen; matching familial genomes is very complicated, particularly as relationships become more distant.
Should I be worried about my DNA data getting into the ‘wrong’ hands?
Professor Metcalfe: A lot of people making their DNA data available online, mainly through ancestry sites, don’t realise that it doesn’t belong just to them; it also belongs to their family.
We share 50 per cent of our genome with our parents and siblings, and 25 per cent with our aunts, uncles and grandparents.
That data can end up in all sorts of places.
Some companies will sell de-identified data to other companies for research and development purposes, What’s unclear is what happens to that data if a company folds or is bought by another company.
There are also concerns about how DNA data could be used in the future. For example, you can access your phone with your fingerprint but one day your DNA sequence may become your identity.
There’s also the potential for genetic discrimination or, in a far-fetched scenario, for stolen DNA to be placed at a crime scene so the real culprits avoid prosecution.
But these issues were not a major concern for most people in our study.
Will following the advice offered by a genomic wellness test make a significant impact on my health?
Ms Hickerton: A significant minority of our participants had completed genomic wellness tests.
These are often ordered through practitioners like naturopaths or nutritionists and they promise clients a personalised prescribed diet and exercise regimen, based on their unique genetic make-up.
We found these sites sometimes make big promises about people’s health that they are unlikely to deliver on. Tests tend to be expensive, particularly when combined with consultation fees and supplement purchases.
There is some good science underpinning these tests. There are some genetic variants that mean our metabolic profiles vary, but we need to be careful because so many health outcomes are due to environmental factors and are not pre-determined by our DNA.
Professor Metcalfe: Often reports are based on individual genetic variants that can have opposite effects and some participants said they didn’t know what to do with that information.
If practitioners don’t have a genomics background, their interpretation of test results may not be accurate and often the advice offered is quite common sense – like exercise regularly, eat less sugar and eat more vegetables.
We found people who do these tests are searching for answers they haven’t been able to find in conventional medicine. They may be experiencing chronic unwellness or symptoms that are difficult to pinpoint, like fatigue or headaches.
But often, the biggest benefit people reported was having someone talking to them and taking their symptoms seriously, rather than being told ‘it’s all in your head’.
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