today warned that parents will be misled about their child's health risks if
they buy genetic tests online, and called for regulation of the tests. A study,
published in the journal Pediatrics today, finds that parents who buy 'direct
to consumer' gene tests for themselves are likely to consider testing their
children, if they think this will tell them something about their child's
genetic health risks (1). Previous research has found that at least three commercial
gene test companies (23andMe, deCODEme and SeqWright) test DNA samples from
children, whilst other companies refuse to do so (2).
"The entire commercial gene test industry is based on a false premise that companies can predict your genetic risk of common diseases such as heart disease, diabetes and cancer" said Dr Helen Wallace, Director of GeneWatch UK. "After decades of misleading propaganda it seems some parents think they will get meaningful results if they buy such tests online. People who have concerns about their children's health should go and see their doctor, not buy these tests over the internet."
The study published in Pediatrics today suggested to parents that they would be able to learn their children's genetic risk of lung, colon and skin cancer and of heart disease, high blood pressure, high cholesterol, type 2 diabetes and osteoporosis. None of these tests will provide meaningful results because these diseases involve multiple biological and environmental factors which interact in complex ways. There is no significant inherited component to lung cancer, which is largely caused by smoking or exposure to pollutants such as asbestos. The other diseases listed are mainly caused by poor diets and lack of exercise. Different commercial companies frequently give different results for a person's genetic risk of these diseases (3).
Although most cases of common diseases in most people are not predictable from a person's genes, rare familial forms of cancer and heart disease exist in which genetic mutations can play an unusually important role. In high-risk families, access to specific genetic tests supported by medical professionals is needed, but ethical guidelines are clear that tests for adult-onset diseases should not be offered to children.
"Most diseases in most people are not predictable from a person's genes," said Dr Wallace, "But in rare cases, some people could get some serious or frightening information. Children should not be tested for adult-onset diseases: they should be allowed to decide for themselves, with medical advice, when they grow up."
Today's study does not show that most parents want to test their children, only that parents who buy online gene tests for themselves may be more likely to consider this. In reality, the market for such tests is likely to be small. The gene test company 23andMe is the market leader in the sale of gene tests online, but has only sold 85,000 tests in 3 1/2 years, despite featuring on the Oprah Winfrey show and the front page of Time magazine. The gene test company DeCode, based in Iceland, went bankrupt in 2009, although it continues to trade as a private company. Very few commercial gene tests are thought to have been sold in Europe. The US Federal Drug Administration (FDA) and the European Commission (EC) are currently considering whether to regulate the sale and interpretation of genetic tests.
The tobacco industry funded most of the early research that claimed that gene tests would predict which smokers would get lung cancer because they wanted to promote the idea that most people could smoke without getting the disease. This idea was endorsed by leading scientists in the run up to the Human Genome Project in order to secure funding for the project (4). The food industry also funded similar research to promote the idea that hypertension, type 2 diabetes and obesity were genetic diseases, rather than largely being caused by the high levels of salt, sugar and unhealthy fats in processed foods (5). Although scientists have now found many genes linked to common diseases these have very small effects and they have failed to explain why most diseases run in families. This is due to the importance of smoking, diets, pollution and social and economic inequalities, which also run in families, and to the complexity of these diseases.
For further information contact:
Dr Helen Wallace: 01298-24300 (office); 07903-311584 (mobile).
Notes for editors:
(1) Tercyak, K, et. al. Parents' attitudes toward pediatric genetic testing for common disease risk. Pediatrics. Published online 18th April 2011.
(2) Borry, P. et al. (2009) Direct to consumer genome scanning services: also for children? Nature Reviews Genetics, 10, 8.
(3) Rival genetic tests leave buyers confused. The Times. 7th September 2008. http://www.timesonline.co.uk/tol/news/science/article4692891.ece
(4) Wallace, HM. Big Tobacco and the human genome: driving the scientific bandwagon? Genomics, Society and Policy 2009, Vol.5, No.1, pp.80-133. http://www.gspjournal.com/
(5) GeneWatch UK briefing: History of the human genome. June 2010. http://www.genewatch.org/uploads/f03c6d66a9b354535738483c1c3d49e4/HGPhistory_2.pdf