Direct-to-consumer genetic tests raise concerns

The recent explosion of genetic tests being marketed to consumers has led to calls for the market to be regulated, and for the clinical utility of the tests available to be validated.

The increase in genome association studies has led to the discovery of genetic markers for various diseases, with the result that 27 companies now offer online tests directly to the public to determine their propensity to diseases such as Alzheimer's or certain cancers. Companies like de-CODEme and 23andME offer tests for around £500 that will calculate a persons' risk of 20 diseases. Linda Avey, co-founder of 23andME, will not reveal how many consumers have paid for the test, but stated that, 'there's so much interest and pent-up demand for this'.

However, there are warnings on several fronts. Firstly, many of the diseases that these suppliers claim to test for involve multiple genetic variations. In many cases the genes involved are not yet known, and furthermore, the potential for these variants to interact both with each other and with environmental factors makes it far from simple to predict propensity for development of the disease. There is concern not only that the test results might not be accurate, but that consumers will not be given the guidance needed in order to interpret the results.

To be told that you have a higher than average risk of developing Alzheimer's will not tell you whether you will actually develop the disease, when you will develop it, or whether lifestyle changes could prevent you from developing it. Considering the lack of treatment currently available for many of the diseases included in the genetic testing, many commentators have questioned their usefulness.

Kathy Hudson, director of the US Genetics and Public Policy Centre, said 'my big concern is that these tests are massively under-regulated...there's nobody looking seriously at whether the claims these companies are making about the tests are accurate'. There have been calls for the US Food and Drug Administration to conduct a review of all genetic testing, due to fears over the validity of the test results.

There are also concerns over the psychological effects the results of these tests could have. Writing in The Times, Mark Henderson obtained his genetic profile from de-CODEme. He commented on the lack of genetic counselling available, and the fact that many consumers could find the information confusing and worrying. He wrote, 'many will approach their GPs, who have little specialist knowledge of genetics and may struggle to make sense of the data in a ten-minute consultation. There is a danger of an increase in the ranks of the worried well, creating an extra burden for the NHS'.

Finally, there are still questions over the privacy of a person's genetic information.  Many have argued that a person has the right to know their own genome, however, there are worries that the information could be misused, misrepresented or misunderstood.