Would you like to ask DNA detectives to predict if your child might have cancer?

Jessica Gray was in the garden in May 2018 when her phone rang. The fact that it was her husband, Jon was not unusual; he always called to go home after work. But when she heard her voice, she knew immediately that something was wrong.

"He said," This is bad news, she has it, "recalls Jessica, 40, a teacher and mother of a child from London. "It was as if someone had hit me in the stomach. The whole world has stopped. '

It had been several weeks since Jessica had posted a sample of saliva taken from their eight-year-old daughter Elizabeth. Although Jessica knew that the results would come, it did not stop the news from appearing as a devastating blow.

"I felt a wave of sadness and another wave of illness," she says. "My lovely little girl was a carrier of the mutated BRCA1 gene," which means she had an increased risk of ovarian and breast cancer.

Jessica had her daughter tested for DNA at home to find out if she had this gene, after Jon and she did the test and it was found.

The home DNA testing market is booming. The industry is expected to account for 17 billion pounds by 2024 and, according to the MIT Technology Review, many people have purchased a home test in 2018, as was the case each year before. In the next two years, more than 100 million people are expected to have sent a sample.

There are now dozens of companies offering to reveal your DNA secrets.

You simply need to take a cotton swab or collect saliva and send it to the company's laboratory in a prepared envelope. They then analyze the sample to find out everything from your probability of having dimples to the origins of your ancestors. And many genetic tests also plunge deeper into your health.

RISING NUMBER OF TESTS FOR HEALTHY CHILDREN

The tests look for gene variations (called "variants") that researchers have discovered are associated with a higher risk of disease. Each society has a different list of desired variants, but these may include those associated with Alzheimer's disease, Parkinson's disease and various cancers.

And that's what seems to motivate many customers to use the credit card – and parents in particular.

"Now that we can sequence a child's genome in good health, we can use that data throughout life to keep it healthy," says Dr. Brandon Colby, an American geneticist specializing in personalized medicine. , and author of Outsmart Your. The genes.

"Only by understanding our DNA can we become smarter than our genes," he adds. "By using the valuable information obtained from the child's DNA, many personalized preventive measures that can be implemented during childhood help reduce the risk of cancer, heart disease and even Alzheimer's later on. in life."

Dr. Colby, whose entire family has undergone extensive DNA testing, reports that the number of families with healthy children undergoing DNA testing "is becoming one of the segments of the genomics industry that is experiencing the strongest growth ". Indeed, a company, tellmeGen, which offers "the most comprehensive genetic test" for children and adults starting at £ 169, told Good Health that it was processing hundreds of tests every month under 18 UK.

But this seems to be the top of the iceberg DNA tests: in an exclusive report for Good Health, the Arlington Research market research agency has investigated 1,000 elderly British parents under 18 years old. More than a third of them had considered using a DNA test at home for their child, 15% admitting that they had already done so.

Reasons range from wanting to know their ancestors (22%) or traits such as academic ability (28%) – but more than half, by far the largest group, want to know more about their child's health. .

That's what pushed Jessica and Jon, a 40-year-old filmmaker, to ask Elizabeth to spit in a tube. Last year, the couple spent themselves a test (at the price of 100 €), motivated by the desire to know their ancestors. Jessica's results, which she received after six weeks, did not reveal anything remarkable.

But Jon's test revealed that he carried the BRCA1 gene mutation, which slightly increased his risk of breast cancer – about one in every 100 men with the defective gene developed the disease – and perhaps even a cancer of the breast. prostate.

More worrying for the couple, its results meant that there was a 50% chance that Elizabeth would also be transferred.

According to the charity Ovarian Cancer Action, women with the defective BRCA1 gene have a 40% to 60% chance of having ovarian cancer, compared to 2% in the general population; and a breast cancer risk of 60 to 85%, compared to 11% in the general population.

"With these numbers, we did not need to think," says Jessica. "We just think that if it's a carrier, we can search all we can and keep an eye on all medical developments. We would be in better control. "

We feel that we are a step forward

As the NHS did not look at children, the only way the couple knew about Elizabeth's genes was to go back to a private company. They informed their doctor of their plan.

"The GP was open, explaining both the pros and the cons," says Jessica. "The only reason they said not to do it would be that it would be sad to know if she was a carrier. But that did not seem like a good reason. "

So, shortly after receiving their own results, they bought a 23andMe test for Elizabeth.

"When he arrived, she was very excited," recalls Jessica. "We had explained the descent part and we could tell if it was more like mom or dad – but we did not mention health.

"I felt a bit sad thinking that this could be a Pandora's box, but that it was the right thing to do."

It is a feeling that is only getting stronger since they received the results last May. For Jon, knowing he had passed on the gene was "a tragedy".

"But I feel lucky that we know, and lucky, we live in a time when these things can be discovered and where we can act," he adds.

"It has been difficult to have discussions about the reality of future breast surgery," adds Jessica. "To see a graph showing the chances of doubling cancer in the late 1920s for people with the mutated BRCA1 gene is very difficult.

"But at least we can feel a step forward. When Elizabeth is 19 or 20 years old, she can freeze eggs (in case a cure or cancer cure affects her fertility) or if she plans to have children, we can say, "Actually, it would be maybe a good idea. Do it now".

"Of course, we hope she will never have any health problems. But it is so much better to know that she is a carrier, even with the anxiety she arouses. "

WHAT IS THE SECURITY OF YOUR DATA?

But not everyone is so sure, especially since home DNA testing has been raised about data privacy.

Dr. Hannah Critchlow, neuroscientist at the University of Cambridge, warned last week that some companies were selling their clients' personal data to third parties such as pharmaceutical companies.

For Toni Hargis, a 57-year-old writer, this is a major concern. That made him regret giving a test to his son, Cal, eight years ago.

"In 2011, Cal was doing a school project on her family tree when I saw an advertisement for 23andMe and thought it would be fun," says Toni, who lives in Surrey with her husband Mark, 59, and Cal, 16 years old.

"I got the test, signed the papers to give him permission to test it, he spit in the tube and everything went away.

"You receive an email and log in to get the results. We discovered that my husband's haplogroup [a group of people who share ancient origins] is from Europe and goes back to an Irish ancestor.

"My haplogroup was located in northern Europe and was the most heavily represented in northern Germany. Since then, updates have been updated to show that Cal is 98.8% European, with some sub-Saharan and Asian roots. "

Then, about a year later, the testing company also started giving basic health indicators. It keeps your DNA for years and whenever a more detailed analysis is available, you receive a notification and can log online to view the details.

"This time, the variants of Cal's DNA have been listed," says Toni. "He had the variant of hemochromatosis, a disease characterized by an accumulation of iron in the body for many years. It meant that it was possible to develop it. "

However, Toni was not too worried, she said, and only spoke to the GP about a year later, when she herself had a blood test. which revealed high levels of iron.

The negative hemochromatosis test was reminded of him, but it reminded him of Cal's results.

"I felt ridiculous, but they took me seriously," she says.

Hemochromatosis, a potentially fatal disease if it is not diagnosed or treated, can lead to heart disease, arthritis or liver cancer.

"They gave Cal a blood test, which showed he had a high iron content," says Toni. "They referred him to a hematologist who decided to monitor Cal, and gradually his iron content decreased and he did not have symptoms of hemochromatosis."

Toni and Cal have changed their way of life knowing that they contain a lot of iron, for example by avoiding red meat and green leafy vegetables.

So is she happy that Cal has passed the test? "Honestly, no," she says. "If I could go back, I would not do it. 23andMe allows you to refuse to share information with other data users, which I have done. But I'm still concerned about data security.

"It's not about 23andMe, it's the entire private sector testing. You read every day that organizations are hacked; I have twice needed a new credit card. I would simply prefer that his DNA not be there. "

GENES DO NOT TALK ABOUT ALL HISTORY

There are also questions about the usefulness of the tests.

They may tell you with certainty that your BRCA gene is defective, but that does not mean that you will get cancer, because many factors are at stake, says Dr. Jonathan Roberts, genetic counselor at the Wellcome Sanger Institute of Cambridgeshire.

"The risk of breast cancer in carriers of [the faulty] BRCA1 or BRCA2 is between 38 and 87%. It's a broad spectrum and we do not know why some people are at the bottom of the hierarchy and others above. It can be genetic factors, lifestyle, environment, etc.

It is also important to understand that these tests do not look for everything. The key, says Dr. Roberts, is something called "negative predictive value".

"That is, what are the chances that a negative result is really a negative result?", He said. "If a test only looks for a few mutations, the negative predictive value is lower than that of the whole gene. It's the difference between looking for some common spelling errors rather than doing a full spelling check. "

23andMe is also clear about this. He told Good Health: "The 23andMe tests involve three of the most studied BRCA variants, which also present a clear and documented risk of breast and ovarian cancer. However, since there are thousands of BRCA variants, a client can receive a "zero variant" result for one of the three people tested and remain positive for the other undetected types. "

Another problem is that of autonomy, adds Dr. Roberts.

"We do not offer predictive genetic tests to children for the conditions that will affect them when they are adults," he says. "I sympathize with parents who want this service. I have had patients who have a history of cancer and want to have their children tested. There is clearly frustration and anger that it is not accessible to them.

"But here is the principle of autonomy: should not it be the choice of the child? In other words, you may want to know your child's outcome, but would you have been satisfied with your outcome in the hands of your own parents? "

Not that it slows the test wave. And as costs continue to fall, these numbers should increase further.

For Jessica and Jon, receiving Elizabeth's results meant deciding, and how, they would tell her what they knew.

"We had different perspectives on this," says Jessica. "Our generalist said that if you transmitted information in droves all your life, it was less of a shock. But another doctor said that it was useless to say anything until she was older, because research could change everything before. "

The couple chose to follow the GP's advice, occasionally mention the problem and answer Elizabeth's questions. "We said things like," My aunt can not come today, she has a doctor's appointment, "Jessica says.

"If she asks me why I'm going to tell her," She has a gene that means doctors want to look at her. "These are small things nicely mentioned here and there."

Jessica knows it's not an easy path. Learning that Elizabeth is a carrier sometimes means that she looks at her a little differently.

"If I have a glass of wine, heard about cancer, and walks around the room, I look at it and feel really sad," she says.

"It's just knowing she could go through there. But then, I think this knowledge provides a sense of security and I have some control. I will always be grateful to the test for this. "

A 23andMe spokesperson said: "23andMe implements physical, technical and administrative measures to prevent unauthorized access to or disclosure of information, to maintain data accuracy, to ensure the appropriate use of information. information and to protect personal information.

"Beyond the private laboratory we work with to process your sample and deliver your results, your sample and genetic information will not be shared with any other entity unless you give us written permission. "

The spokesman added: "We do not share any information with employers, insurance companies, law enforcement agencies or public databases."