London - Apparently, I am a woman of hidden talents.
Not only am I able to tolerate the bitter taste of Brussels sprouts, but I’m not affected by alcohol flush reaction - for those unlucky enough to have it, this means just one drink can make them feel dizzy and sick and turn bright red.
I also have a photic sneeze reflex - meaning I’m more likely to sneeze moving from shade into sunlight. I discovered these rivetting pieces of information a few weeks ago after undergoing a £125 (about R2 200) gene test you can now buy from Superdrug.
The results revealed an astonishing amount of information, including the famous people I am genetically related to - it seems both Marie Antoinette and Hollywood actress Susan Sarandon are long-lost relatives.
But while such knowledge might enliven dinner party conversation, the other details provided are more significant and raise serious questions about whether such tests - which can also be bought online - should be so easily available to consumers.
For as well as physical traits, the test provides more than 100 pieces of genetic information about the risk of inherited conditions and how you will respond to certain medicines.
The test is marketed under the name 23andMe - so named as each of our cells contains 23 pairs of chromosomes, on which our genetic blueprint, or DNA, is based. Taking the test is easy - dealing with the information it reveals is more complicated and potentially fraught.
The test itself involves simply spitting into a tube, sealing it and sending it back in the prepaid envelope to 23andMe’s labs in California for analysis. Four to six weeks later, you receive a detailed report online.
The company states that its mission is to ensure that individuals can access, understand and benefit from the human genome.
That way, they can take better care of themselves, perhaps with regular health checks so that an illness can be caught - and treated - early. All very noble.
But what concerns Gareth Evans, professor of medical genetics and cancer epidemiology at the University of Manchester, is the impact of taking home genetics tests for serious illnesses such as breast cancer.
The 23andMe test claims to tell whether people carry mutations of the BRCA1 and BRCA2 genes - carriers have an up to 85 per cent risk of developing breast cancer and up to 55 per cent risk of ovarian cancer.
These tests are already available on the NHS for those concerned about family history of both diseases.
“But women undergoing these tests at family history clinics are also offered counselling,” says Professor Evans. “They need to understand the implications of a positive test (i.e. they have the gene mutation) and what their potential options, such as surgery, involve.”
He also worries that women who test negatively may be lulled into a false sense of security.
BRCA is just one of 96 gene variants which account for breast cancer, he says. “So someone could think they are fine because they come back negative for the BRCA mutation and be less vigilant about any changes that could be a sign of cancer.
“The majority of breast cancer is not genetically inherited; even if someone is free of BRCA1 and 2 mutations, it does not mean they will not get breast or ovarian cancer.”
Getting the information about whether you’re at risk of such serious conditions without any support is indeed a deeply unsettling experience, as I discovered.
While all other results are immediately available in the test report, those relating to breast cancer, Parkinson’s and Alzheimer’s are “locked”, which means you have to agree that you understand what you are about to be shown.
However it takes only two clicks to gain access. Even though I have no family history for any of these diseases, I initially interpreted the fact I was locked out as a sign I was to receive dreadful news.
Thankfully, I didn’t - although my gene test for Alzheimer’s “could not be determined with confidence”. This means they didn’t get enough information to determine whether or not I had three gene variations - including one known as the APOE4 - associated with the condition.
But Dr Clare Walton, research manager at Alzheimer’s Society says there still isn’t enough knowledge to use such genes as a diagnostic tool.
“We know certain genes can increase your risk of Alzheimer’s disease, including APOE4. However, not everyone with the APOE4 gene will develop the condition.”
Even so, my lack of results in this part of the test has inevitably left me paranoid - only yesterday I left my keys in the car by mistake. Was that a sign that I’m at risk?
Joyce Harper, professor of human genetics and embryology at the Institute for Women’s Health at University College London, says there is a certain pointlessness to testing for diseases which have no cure, even if the tests could say with certainty that a person was at risk.
“Parkinson’s is a serious disorder of the brain’s motor centre and current treatment is effective in a few people but only ever serves to slow the disorder, not cure it,” she says. “I simply don’t understand who this test is aimed at and what you are to do with the information. Parkinson’s and Alzheimer’s are both, sadly, incurable. What’s the point of knowing?”
On a practical level, Professor Harper believes the fall-out of this sort of testing will have to be shouldered by the NHS as people may go to their doctors requesting further tests, taking up valuable NHS time.
Two years ago, 23andMe was stopped from giving information about disease risks and drug response to US customers.
The US health watchdog, the Food and Drug Administration, cited the example of the BRCA genes, saying false-positives could lead to patients undergoing unnecessary pre-emptive surgery, such as a mastectomy.
However, earlier this year the FDA ruled the company could market a gene test for a specific condition known as Bloom syndrome. The UK authority, the Medicines and Healthcares Products Regulatory Agency (MHRA), seems to take a more relaxed approach.
It told Good Health: “People using these products should ensure that they are CE marked [the letters show a product has been approved under European regulations] and remember that no test is 100 percent reliable so think carefully before using personal genome services.
“The information provided by 23andMe should not lead you to make any changes without consulting your healthcare professional.”
But aside from the moral questions over such tests, do they help us make better lifestyle choices?
My test revealed that I was lactose intolerant due to lower levels of substances which break down the sugar found in milk. I found this astonishing, since having dairy has never been a problem.
Dr Steven Mann, a consultant gastroenterologist at the Royal Free Hospital in London, says he would be concerned if people cut out dairy because of a home test.
“Most adults with lactose intolerance have what’s known as ‘acquired lactose intolerance’ - triggered by food poisoning or a virus which damages the stomach lining, rather than a genetic malfunction. So a test would be an unreliable marker.”
And he says you shouldn’t cut out dairy entirely - it’s a vital source of calcium, important for bone health.
“We tell people who are lactose intolerant to see how much they can manage and then cut back if it affects them with cramps or diarrhoea.
“Or we leave it for six to 12 months and then slowly reintroduce foods. For these reasons, this kind of test is absolutely useless.”
Furthermore, the test analyses 12 genetic variations related to how sensitive people are to medication, as well as the likelihood of side-effects. These drugs include the blood thinner warfarin and proton pump inhibitors, given for acid reflux.
“This is quite complex information and is only relevant if you were having a particular treatment,” points out Professor Harper, who took a 23andMe test for a Radio 4 programme and was found to have a reduced reaction to a drug which treats deep vein thrombosis.
“It told me I had have a five percent risk of this drug not working. But they don’t say what that extra five percent risk is compared to.’
I was told I had a “reduced” response to clopidogrel, commonly prescribed after an angina attack or heart surgery to help prevent blood clots. According to 23andMe, this means I “may have less protection from heart attacks, strokes and death”.
Should I be panicking? Dr Glynn Thomas, a consultant cardiologist from the Bristol Heart Centre kindly assures me I shouldn’t.
He says: “As doctors we would be monitoring you anyway, and I’m not sure knowing this about a specific drug is worth the anxiety.”
Meanwhile, I gather that my kinship with Susan Sarandon is down to the fact that we share an ancestor who bequeathed us - and countless others - the same tiny bits of DNA.
Direct-to-consumer genetic analysis is clearly here to stay, but until the science is refined, says Professor Harper, this sort of test remains “pointless”. As for me, I don’t plan any huge changes to my lifestyle - or family parties. Sorry Susan, don’t hold your breath for an invitation.
Daily Mail