The genetic goldrush
Genetic testing is cheaper than ever. Companies are lining up to sell wine, shoes, fitness plans and more – all tailored to your DNA. But just how feasible are their claims?
Apps and services offering DNA-based advice on everything from planning a workout to choosing a wine are increasingly common. Kat Arney finds out more.
n less than two decades, the science of human genomics – studying the genetic makeup of individuals and populations – has changed beyond recognition. The first full human genome sequence took 10 years and cost nearly $3bn to deliver (at 1991 prices). Today you can spit in a tube, pop it in the post, and expect an email to arrive within weeks detailing thousands of variations within your DNA linked to traits, health and heritage, at a fraction of the cost.
Unsurprisingly, enterprising companies have been quick to jump on the genomic bandwagon, offering everything from fitness plans to personalised wine choices based on your genes. But is it really possible to get such detailed information from a glob of your saliva? DIRECT TO YOUR DOOR The story of direct-to- consumer (DTC) genetic testing really starts in the early 2000s. At this time, relatively little was known about how small differences in DNA sequences between people – known as single nucleotide polymorphisms, or SNPs (pronounced ‘snips’) – mapped on to disease risk or physical traits such as height, weight or taste preferences.
Nonetheless, companies sprang up offering pricey nutritional advice and supplements based on testing a handful of SNPs. Given the lack of solid scientific evidence linking SNPs to characteristics, these were dismissed by the authorities as being medically unproven and ambiguous.
By the middle of the decade, the genetesters had started to wise up. Rather than purporting to offer any kind of medical advice or diagnosis, which would lead them to fall foul of regulators such as the US Food and Drug Administration (FDA), they now claimed to provide their SNP tests purely for informational and educational use. By 2009, more than 500 SNPs had been reliably linked to the risk of diseases such as cancer, and this
was growing year- on-year. Anyone with a burning biological curiosity and a thousand dollars to spare could now sign up to ‘get their genomes done’. Yet despite their growing popularity, when experts analysed the results of these tests they found them to be misleading or even just plain wrong, driven by deceptive marketing rather than sound science.
Put off by regulatory crackdowns and a limited consumer base, many of the original SNP-based personalised genetics firms closed down or sold out to larger firms. But there have been a few survivors, and these companies continue to link SNPs to a wide range of disease risks, physical traits and ancestry. And as the pace of technology has accelerated and costs have plummeted, the genetic marketplace is opening up once again.
One of the big boom areas is in genetic ancestry services, with companies offering to find your longlost genetic relatives and trace your roots around the globe. Some of them even tell romantic stories of ancient tribes, fierce barbarians or sophisticated
“THERE’S VERY LITTLE HARD EVIDENCE THAT A GENETICALLY-TAILORED DIET IS ANY MORE EFFECTIVE THAN A GENERIC ONE”
artists lurking up the ancestral family tree.
It’s certainly possible to pin genetic heritage to certain parts of the world, particularly for populations rather than individuals (though even then it’s a relatively imprecise science), as well as figuring out what percentage of your genome came from Neanderthals. But many scientists working in the field of human genetics and evolution are less convinced. For example, researchers from the Molecular and Cultural Evolution Laboratory at University College London have investigated and debunked the more dubious claims as little more than “genetic astrology”. They argue that the complex patterns of human mating and migration make it tricky to tease apart the tangled genetic threads in each of us with any degree of accuracy.
The other hot topic in DTC testing comes under the broad banner of ‘lifestyle’. Companies now offer the chance to ‘hack your body’ and ‘boost your human potential’ with all kinds of dietary and fitness advice tailored to your personal combination of certain SNPs. Some recommend combinations of ‘genetically selected’ vitamins and dietary supplements, while others even offer personalised meals delivered direct to your door. But although these tests all claim to be supported by science – and while it’s true that the SNPs they test for have been linked to weight, metabolism or other physical traits in large studies – there’s actually not very much hard evidence available to suggest that following a genetically-tailored diet and fitness plan is more effective than following a generic one.
In fact, a large randomised controlled trial carried out by scientists at University College London and published in 2015 showed that giving people a weight loss programme alongside information about their personal version of a gene called FTO – which is associated with body weight – made them more likely to think about losing weight, but wasn’t any more effective than the programme alone.
Another study showed no change in behaviour, at least in the short term, for people who were given genetic information about their risk of type 2 diabetes – although on the plus side, there was no increase in worry or anxiety either.
“My feeling is that [DTC tests use] quite a clever marketing strategy,” says Dr Caroline Wright, programme manager for the UK’s Deciphering Developmental Disorders study and scientific lead at Genomics England. “I think the science behind some of these things is going to be tenuous. There are research papers that link variations in DNA with certain attributes, but it doesn’t necessarily mean that if you test that particular variant in a particular person it will be predictive for what they like or what they can do.”
MORE DATA, MORE PROBLEMS
Taking advantage of the ever-shrinking cost of DNA sequencing, DTC companies are now moving on from SNPs and taking a deeper look at the human genome. The next step is exome sequencing – reading the entire genetic recipe of all 20,000 genes in the genome, without the misleadingly named ‘junk’ DNA that lies in-between.
The first firm into the exome marketplace is Helix, backed by DNA technology giant Illumina. Based on the principle of ‘sequence once, query often’, Helix plans to store customers’ exome data and allow them to access it through an app store, with third-party partners offering gene-matched products ranging from health analysis to lifestyle advice.
The first product on offer is Geno 2.0, which is an ancestry analysis package that’s produced in association with National Geographic. Further partners are in the process of signing up, including a range of academic institutions such as Duke University and the Mayo Clinic. On the less serious side is Vinome, which offers customers regular deliveries of genetically-matched fine wines with “a little science and a lot of fun”.
Whether Helix’s exome-and-app approach offers anything more than the SNP-based ancestry or diet and wellness tests remains to be seen. The thornier issue will come if Helix offers analysis of genes involved in disease. Not only does this skirt the line with regulatory agencies such as the FDA, which demands that medical tests are only available
2 through a doctor, but it raises important scientific issues too.
“There is no doubt that there is a small but important percentage of people who could hugely benefit from exome sequencing, by discovering that they have a specific genetic variant that causes a disease,” explains Wright. “But we know that everybody’s genomes are incredibly variable.”
She points out that while we have robust information on common SNPs that are linked to disease risk, opening this up to whole exomes is a huge leap into the unknown. Most people have at least some rare or unique genetic variations that look like they ought to be harmful, yet are completely healthy (see the cover feature of BBC
Focus, September 2016). The big challenge is working out how all the tweaks and changes in someone’s genome work together to influence their health.
“We don’t have a huge amount of data, and the potential for overdiagnosis and telling someone they have a genetic predisposition [towards a certain disease] is going to be quite tempting,” says Wright. “You can tell a story around pretty much anyone’s exome, and everyone will have potentially interesting-looking variants. Some of these will genuinely cause disease, but many will not.”
Helix declined to speak to us, saying that their service will only launch in the US in 2017, and that there are no imminent plans to bring it to the UK.
But with the cost of sequencing falling rapidly, it might only be a matter of time – especially as Illumina’s new NovaSeq machine promises to bring the $100 genome within range. Yet for all the excitement and talk of high-tech apps fuelling the consumer genomic revolution, the same issues remain that have always dogged genetic testing, particularly around privacy, consent and the question of who gets access to the data.
Yet for all the excitement and talk of high-tech apps fuelling the consumer genomic revolution, the same issues that have always dogged genetic testing remain, particularly around privacy, consent and the question of who gets access to the data. Whiling away some idle time in a genetic app store is likely to be a harmless curiosity for most people, and at a time when it’s important to encourage the public to engage with genetics, it seems churlish to raise a note of caution. But wringing data out of your genome could raise more questions than it answers.
“THE SAME ISSUES THAT HAVE ALWAYS DOGGED GENETIC TESTING REMAIN, PARTICULARLY AROUND PRIVACY AND CONSENT”
“Information about ancestry, fitness and what kind of wine you like might also be mixed in with whether you’ve got high susceptibility to breast cancer or a gene variant that means you’re going to get Alzheimer’s disease early in life,” says Wright. “Those are quite different types of information, but you’ll be able to get it all from your genome. Some of them are fun, and some of them really aren’t.” We’re seeing the start of a genomic gold rush: in a few years, having your DNA sequenced and rifling through it could be as simple and fun as browsing TV box sets. But it’s important to remember that these companies hook curious consumers with promises of genetic insights because they want to make money. This is powerful, personal information, with potentially life- changing consequences, and it’s worth handling with care.
BELOW: A printed copy of the human genome fills a whole book
RIGHT: A chip containing DNA is loaded into a machine for analysis
ABOVE LEFT: An autoradiogram showing the order of nucleotide bases in a sample of DNA
ABOVE: A DNA sequence reveals the presence of APO E, a genetic marker for Alzheimer’s