Direct-to-consumer genetic tests: what's in it for you?
Founder of Cambridge Precision Medicine considers on-sale-now DNA sequencing tests
Direct-to-consumer (DTC) genetic tests have been around since the mid-2000s.
The first batch of companies to offer this analysis provided the testing of ‘mispellings’ in the hundreds of thousands for about $1,000.
As technology has progressed and more providers of genetic tests come into the market, prices have steadily come down. If the user wants to see all of the different tests that are available, a good place is DNA Testing Choice, which offers one of the most complete listings online.
Having a look at all of the different choices available there makes one think that genetic testing has not just become a tool, it’s a revolution: there are tests for compatibility of mates, pet testing or immigration testing, just to give three examples. This is just a glimpse of what’s coming.
Genetic testing is fast becoming a ubiquitous companion in our future everyday lives. But is this a race towards a healthier, more secure and longer life? My gut feeling is that there’s a lot of hype, particularly when the tests are performed for healthy people. Why? Because we still are miles away from understanding the molecular mechanisms encoded by our DNA.
On top of that, there’s a lot of misunderstanding about the ‘gene for this’ or the ‘gene for that’. This is not how our bodies work.
Each of the functions in our genetic code, embodied by what we call genes, is an orchestration of different functions of several or many genes. Some traits, such as learning ability, are complex and require many genes. For sure, we know that certain mutations (ie versions of the gene) such as those in APOE increases the the chances of suffering from Alzheimer’s.
The hope, though, is that at some point we will be able to ascertain with great accuracy the contribution of genetics to any particular trait. We can already quantify them with twin studies but, for the vast majority, we still do not know how exactly those functions map to our genes.
My family has probably been one of the most studied families genetically in the world. I was an early adopter of direct-to-consumer genetic testing and since 2009 we have studied our DNA in a variety of methods and tests.
How much have we learnt? Well, it depends on how you look at it. For example, I learnt I have a 30 per cent chance of having prostate cancer which, by the way, is now the leading cause of cancer death in the Western world. But what does a 30 per cent chance really mean? Perhaps it means something to some people and to others nothing.
In the future, we are going to have to move more into the realm of probabilities as medical practice slowly incorporates genetic knowledge. We will also find incidental findings: things that we find that were not expected (ie biological father not the same as the one expected).
With my family studies, we were able to confirm that my aunt, who had several episodes of thromboembolism, did appear to have a higher risk of it in her genes. When I talked to her about this, it was clear that the cause of her suffering from this disease should not necessarily be blamed lifestyle choices.
I recommend caution to anyone wanting to have a genetic test. There’s lots of rubbish out there but, if you are able to sift the wheat from the chaff, you might be able to find some actionable outcomes for which you could do something.
However, do not believe right away whatever a genetic test tells you. Make sure that someone like a genetic counsellor or clinical geneticist sees it and is able to interpret it for you.
There are a lot of automated algorithms and software out there to provide results. Sometimes they may be presented in a very ‘scientific’ way, so slick you think they might be right. You may also find that because you have spent some money on this you really want to get your money’s worth.
I have discovered this attitude for myself. New conditions, such as restless leg syndrome – which I didn’t know about and still do not have a clue as to whether I really have it – were part of my genetic test. The result said ‘yes’, and I believed it.
Genetics is just one part of the equation, and it should never be used in isolation, particularly in a diagnostic setting.
It needs to be accompanied by the experience of a qualified professional who can integrate your genetics with your clinical history and background.
So these tests are here to stay but, before we reach a point in which they are reliable in all respects, they still need to evolve and improve.
Cambridge Precision Medicine is based at the Future Business Centre in King’s Hedges Road, Cambridge.
More by this authorManuel Corpas
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