Barbara Ellen using a home DNA-testing kit. Photograph: Sonja Horsman for the Observer New Review for the Observer

There may come a time in everyones life when they find themselves sitting at the kitchen table on an otherwise unexceptional weekday morning, drooling saliva into a test tube in the spirit of scientific inquiry.

The spit is for one of the home genetic-testing kits Im sampling. A growing number of these kits (brands such as 23andMe, DNAFit, Thriva, MyHeritage DNA, and Orig3n) promise to unlock the mystery of your genomes, variously explaining everything from ancestry, residual Neanderthal variants, bioinformatics for fitness, weight loss and skincare, to more random genetic predispositions, denoting, say, the dimensions of your earlobes or the consistency of yourearwax.

More controversially, some of these kits profess to tell you your biological (as opposed to actual age) by measuring the length of your telomeres (in basic terms, the caps at the end of each strand of DNA that protect chromosomes, like plastic tips at the end of shoelaces). Other tests, such as 23andMe, predict higher risks of developing serious conditions, such as multiple sclerosis, Alzheimers and Parkinsons, including the test for BRCA1/BRCA2 (breast and ovarian cancer) that Angelina Jolie famously underwent, going on to have a preventative double mastectomy and surgery to remove her ovaries.

Its easy to do these tests; its usually just a case of collecting your own samples at home, filling in short, basic questionnaires, posting the packages, and then logging on to interactive websites for confidential results (all the kits I tested used outside laboratories). With an array of price ranges and options, from one-off DNA-blitzes to targeting specific health areas, to fitness/wellness tracking, its no surprise that these kits are proving to be very big business and the field is primed to get even bigger, with a global market estimated to be worth around 7.7bn by 2022.

Saying that, whats it all for? Some individuals, such as Jolie, have the kind of family histories that give them good reason to be concerned about their health, though, as becomes clear, those people might be better off consulting doctors in the normal way.

Otherwise, the home-testing kits could be said to fit in with our increasingly health-conscious and, if you wish to be cynical, narcissistic times. What says youre special more than finding out everything about yourself, right down to the nitty-gritty of genetics? In this way, these kits could be viewed as the latest plaything of the worried well. You could see how the scientific approach would appeal to the health-obsessed of all sexes and ages, your marathon runners and serious gym-goers, who take their fitness extremely seriously.

Another key customer type could be people like myself, hurtling through middle age, perhaps just starting to feel the cold bony hand of mortality clamp down on their shoulder. People, who, in the past, may not have exactly prioritised their health, who are starting to wonder what may be in store for them and who are in the (Hypochondriacs R Us) market for some hard-core insight andadvice.

Which is all very well, but do these kits work and deliver the service they promise and what about the wider ethics and implications of home genetic testing? Is it always wise for generally under-informed, under-prepared consumers to meddle in the highly complex, nuanced arena of genetics, risking confusion, complacency or even outright panic and anxiety when confronted with ostensible bad news (which may not even be true)?

The first kit I try is Thrivas baseline test (49), which, like all its products, checks your blood. The box arrives promptly enough (containing spring-loaded needles, a little collection tube, antiseptic wipes, plasters, etc), but theres a problem. The idea is to prick your finger and massage blood into the tube, but I just end up making my fingers sore and what I get out barely smears the top of the phial. Maybe its just me, but it turns into a right faff. In the end, I take advantage of Thrivas service to send someone out to take a sample of blood from my arm.

When we speak, co-founder Hamish Grierson describes Thriva as a lifestyle brand with medical-grade testing at the back end, an opportunity for people to see themselves as consumers rather than patients. Grierson gives examples of people who have benefited from Thriva testing, sometimes picking up early on serious issues. As for alarming people, Grierson says that Thriva has on-site facilities to discuss results and is intended to be complementary to the NHS rather than replacing it: If there are questions we cant answer, were very clear that people should pick it up with their GP.

When my results appear, they show nothing bad. If anything, its anticlimactic: cholesterol, vitamins, liver proteins and the like are all in the normal range, with only ferritin (iron stores) slightly high, with a recommendation to go easy on any iron supplements. My problem with the baseline test is that, unlike Thrivas other products, clients are supposed to have one every three months to keep track, but would I really want (or indeed need) to do such a test soregularly?

According to Margaret McCartney, GP, and author of The Patient Paradox, theres a fundamental problem with home genetic-testing kits per se.

My concern is that more and more of these tests are being put out, and people are being persuaded to have these tests done, and they get results back that are very often of very low value and dubious helpfulness, she says. And often people are told to go to see their GP and that then places a direct stress on the NHS, at no cost to the company. The companies make their profits and walk away, letting the NHS sort out all the fallout, the push-back, from the test results, in a way I find absurd. Why should the NHS have to prop up the problems that these companies create?

In McCartneys view, enough testing is already done in this country (sometimes too much) and there are issues of regulation and informed consent. People are given very dramatic reasons to have these tests it could help save your life, it could help improve the quality of your life but where is the actual controlled evidence that these tests have ever done that? Theres no evidence that says doing these tests makes people becomehealthier.

McCartney says that anxious people often contact her, saying they wished they hadnt done the tests. These companies often say that its worth it for the helpful advice. But I can give you really good advice right now without seeing a single test result: be active, have lots of social networks, do work you enjoy, try not to smoke or drink too much, dont be overweight or underweight, eat lots of fresh fruit and vegetables. Nobody needs to get tests done to get that kind of basic lifestyleadvice.

Nor does McCartney care for the worried well narrative. I dont really like the worried well thing because it moves the blame on to the people themselves. I think people are being made anxious by manipulative advertising. People are generally good. They dont want to be worried or unwell just for fun.

Some concerns about the ultimate efficacy of certain home tests seem to emanate from the industry itself. I did a telomere-measuring test (a mouth swab) by Titanovo, based in north Colorado, which came back saying that my telomeres were too short, putting me at 10 biological years older than I am. However, when I contacted Titanovo, it explained that it had stopped telomere measuring and was now concentrating exclusively on its DNA-utilising bioinformatics health, fitness and wellbeing website (analysing client data from other genetic testing sites).

Titanovo explained that it found telomere measuring too inconsistent, with too many super-fit people presenting with short telomeres and unfit people presenting with long ones and, ultimately, everyone receiving pretty much the same advice: start exercising and eating healthily or continue exercising and eating healthily.

Bill Newman, professor of translational genomic medicine in the Manchester centre for genomic medicine at the University of Manchester, and chair of the British Society of Genetic Medicine, says that such tests in this context simply dont make sense and that, usually, telomere testing would only be used in in-depth studies of ageing and diseases associated with ageing. Theres some really brilliant work going on, by some of the best biologists in the world, says Newman, citing Elizabeth Blackburn, who won the 2009 Nobel prize for medicine for her work on telomeres. But theres no evidence whatsoever that measuring a persons telomeres gives any indication about their health or beauty, intelligence, or anything else that might be listed on these sites.

In Newmans view, the genie is out of the bottle with home genetic-testing kits. He says that while the kits could potentially provide data in the future, right now, they lack clinical utility they look at genetic variants that, individually, have a very low chance of predicting specific health risks, as there are too many variables: Its like the Opportunity Knocks clap-o-meter, with some people further along the scale, and therefore more likely to get the condition and then people at the other end of the scale, who are unlikely to get it.

Newman says that theres a basic lack of literacy and understanding about genetic testing, among the public and even other health professionals. People are given false reassurances or made to panic (just because you have certain genetic variants, it doesnt mean that you will develop a particular condition). Newman also makes the point that, in his field, counselling happens before and after testing and, while people with cancer or heart issues nearly always opt to have the test (as they can then take action to varying degrees), often people with conditions such as Huntingtons disease in their family decide not to go ahead because a diagnosis would change nothing for them. In any event, Newman says that, with genetic testing, while there are different levels, intensive counselling is always absolutely key.

All this comes into sharp focus with the comprehensive kits such as the one provided by 23andMe: the one I drool into a tube for (incidentally, 23andMe doesnt test for Huntingtons disease). Most people, like myself, have a low understanding of genetic variants, what phrases such as higher risk or probability actually mean or how to interpret our results correctly. Is it right that ordinary members of the public must navigate potentially frightening and/or misleading results alone?

As it happens, most of the data on 23andMe seems harmless and fun. There are the Neanderthal variants (I have fewer of them than 58% of 23andMe customers, thank you very much), the bizarre earwax/earlobes-type data and, apparently, I have the muscle composition generally found in elite athletes (fancy). On the downside, my lineage isnt as exotic as Id hoped: 99.1% north-western Europe, of which 71% is British/Irish, with just 0.01% Ashkenazi Jewish to offset the genetic monotony. At 149, the 23andMe kit isnt cheap and Im quite tempted to demand a recount.

Then comes the section about serious genetic variants. So far as counselling goes, previously, Id waved away concern for my psychological welfare from the Observers science editor (Im a former goth, I said. My default setting is doomed), but it turns out to be quite daunting. It doesnt help that I initially mistake the full list of potential conditions for my own results, hence (thankfully briefly) thinking that I have higher risk factors for everything going. It makes me wonder how many other people are going to do that?

In fairness to 23andME, it leaves it up to the customer to unlock the more serious results or not. When I unlock mine, I discover that, while Im not genetically predisposed to such things as the BRAC1 or BRAC2 variant, Parkinsons or MS, I have one of the variants for late-onset (mid-80s) Alzheimers. However, I dont have any other markers for Alzheimers or family history or conditions associated with it or anything else listed in the rather lengthy disclaimer, which also stresses that its not a diagnostic result and to seek further advice from your GP if you are concerned.

This is another feature of these genetic-testing sites they are littered with caveats and disclaimers, forever emphasising that theyre not actual diagnostic tests and, if you are really concerned by your results, to seek further advice from your GP or another health professional. As has been pointed out by McCartney, when anything looks serious, ultimately its back to the very GP and exact NHS infrastructure that these kits profess to smoothly bypass.

As a postscript, I eventually end up having an interesting chat with Titanovo about my bioinformatics (distilled from my 23andMe data). One of the first things Im told is that my eyes are green (theyre brown). However, the bioinformatics got my skin type and frame/weight generally right and had interesting (albeit occasionally generic) things to say about exercise, diet, goals, steering clear of too much sugar and so on.

Who knows how much of it made solid scientific sense? However, I have to confess that I rather enjoyed it on the level of an indulgent genome-oriented pampering session, just as I had a hoot with the ancestry/Neanderthal/earlobe data on 23andMe. Where Thriva is concerned, I also noted that it did advanced thyroid tests. Although such tests are available from the NHS, Im hypothyroid myself and I know that sometimes it can be difficult and time-consuming getting tests repeated and it could be useful to be privately tested in this way.

It could be that, in the main, genetic-testing kits such as these could, if promoted and used responsibly, end up zoned completely away from legitimate science and medicine and placed where perhaps they belong, firmly in the lifestyle-extra zone, if and when people think theyre worth it. Though, somewhat tellingly, when I ask Newman if he thinks that any of the genetic testing kits are worth buying, he instantly says: No. Id say, go to the cinema, watch some sport. Spend the money on something nice, something life-enhancing.

What is the project? The 100,000 Genomes Project is an NHS initiative, run by Genomics England, and is the largest national genome sequencing project in the world. On entering, patients have their entire genome, of more than 3bn base pairs, sequenced. This is different from commercially available genetic testing kits, such as those from 23andMe, which only look at very small stretches of DNA in a process called genotyping. The hope of the NHS is that having so much genetic information, from so many different people, will allow groundbreaking discoveries about how diseases work, who could be susceptible to them, how we can treat them, and what treatments might work.

Whose genomes are being sequenced? The only patients having their genome sequenced are those with certain cancers or rare diseases. In some cases, family members may also be asked to participate. To take part, a patient must first be referred by a consultant, before being taken through an extensive consent process to ensure they know what participation in the project means. As well as the genome sequence, Genomics England asks for access to a patients lifetime medical records so that links can be made between their genetics and their individual disease. The NHS has made it very clear that, for many participants, taking part in this project wont help them treat their disease. But it is hoped that the information they provide will go on to help treat others in the future.

Where does the data go? Each patients genome sequence and their medical records are kept in an NHS data centre in pseudonymised form. Researchers from commercial and not-for-profit organisations can get access to the data at the centre if they can prove that they are using it for studies that will further medical science.

What information do the patients get back? Although the project states that most participants wont receive any useful information, patients will be told if something is found in their genome that is relevant to the treatment, explanation or diagnosis of their condition. They can also choose to learn if they have a genetic risk factor for another disease, such as the BRCA1 gene mutation that can cause breast cancer. Genomics England will only look for risk factors that are linked to a disease that can be treated or prevented. Untreatable conditions, such as Alzheimers, are not looked for.

Why 100,000 genomes? The NHS believes that sequencing 100,000 genomes will provide enough information on these diseases while also being cost-effective. In the future, as the price of whole genome sequencing goes down, it hopes to involve more patients and even more diseases.

Agnes Donnelly

Continue reading here:

What I learned from home DNA testing - The Guardian