Direct-to-consumer testing

Have you ever wanted to know more about your genetic make-up? Direct-to-consumer testing is now making this possible through tests you can order online. But is there a more serious side to us having such easy access to all of the information in our genomes? 

What is direct-to-consumer genetic testing?

Direct-to-consumer genetic testing involves a test that can be bought, over the internet, without the involvement of healthcare professionals. It enables consumers to access information about their genetic make-up without having to consult a doctor, nurse or genetic counsellor. The bulk of direct-to-consumer tests are sold by US companies but can be bought by anyone, in any country, over the internet.

They ask you to send back a saliva sample. I did it together with friends..

Jeff

The test requires the individual to provide a sample of their DNA. This is usually through a simple swab, taken from the inside of the cheek, or a spit sample, which is then mailed to the laboratory. The results of the test are then either posted back, provided by email or, in many cases, made available online via a personal account on the company’s website, which can then be updated.

Direct-to-consumer genetic testing: supplying a sample and getting the results

Individuals may decide to involve a genetic counsellor in the process to talk through the potential results beforehand and then help them understand the results once they receive them. However, in many cases, healthcare professionals are not involved at all in the process. This has been an area of much controversy for direct-to-consumer testing. 

What are the pros and cons of this kind of genetic testing?

I've spent a lot of time working on my family history. At some point you reach a dead end...

Josh

On the one hand, direct-to-consumer testing promotes an interest in genetics and an awareness of genetic conditions and diseases. As a result it allows consumers to take a more active role in their healthcare, for example if the results indicate that they may be predisposed to developing type II diabetes they may be more motivated to lose weight and improve their diet.

In addition to this, direct-to consumer testing has a fun element. In some cases, it allows individuals to learn more about their ancestral origins.

Direct-to-consumer genetic testing: looking at your ancestry

However, direct-to-consumer tests do carry risks and limitations. There is potential for consumers to be misled by inaccurate or ill-explained test results and make complex medical decisions without sufficient guidance or thorough understanding of the risks.  As direct-to-consumer tests become more widespread, it is likely that there will be an increase in the number of people seeking advice from their doctors after receiving results that indicate a higher risk of disease. In 2009, the British Medical Journal (BMJ) published a clinical review recommending that doctors take care when asked by their patients to interpret the results from direct-to-consumer tests.

In addition to this, direct-to-consumer tests currently available vary greatly in their accuracy and reliability.

Direct-to-consumer tests currently available vary greatly in their accuracy and reliability.

You have to consider the results of direct-to-consumer genetic testing in conjunction with all the other information about yourself...

John

In 2013, a study published in Nature generated genotype data for 100,000 hypothetical people and predicted the risks of six diseases, including type II diabetes and prostate cancer, based on the methods of three direct-to-consumer companies. The researchers found that the predictions of disease risk generated by the different methods varied significantly, the largest difference being for coeliac disease. This highlights the limitations of direct-to-consumer testing as a clinical tool.

Many direct-to-consumer test panels are associated with complex diseases that are influenced by multiple factors, both genetic and environmental. Consequently, the results can be difficult to interpret and understand. Clear criteria are needed to identify which tests are of clinical relevance. Certification of reliable tests would allow consumers to identify and choose those tests that have been deemed scientifically valid.

Direct-to-consumer genetic testing: considering genetic test results

Regulation

There have been calls for regulation of direct-to-consumer genetic tests from a variety of policymakers around the world.

In 1997, the Working Group on Ethical, Legal and Social Implications of Human Genome Research in the USA laid out three key criteria to help assess the efficacy and quality of genetic tests:

  1. Analytical validity: a positive result occurs if a particular sequence is found in an individual’s genome, a negative result is if the sequence is absent.
  2. Clinical validity: the test is positive in people with a given disease and negative in those without the disease. Positive results predict disease, negative results predict its absence.
  3. Clinical utility: the test’s benefits outweigh the risks.

In August 2010, the UK-based Human Genetics Commission published a ‘Common Framework of Principles’ to set out the standards that direct-to-consumer test providers should follow. It tackled informed consent, marketing, risk communication, genetic counselling and data protection. The commission recommended that tests for serious hereditary diseases, such as breast cancer, should only be provided with the offer of genetic counselling.

Unfortunately, the Human Genetics Commission was disbanded in 2012, after 12 years as an advisory body to the UK Government. The Emerging Science and Bioethics Advisory Committee (ESBAC) was formed in 2012 and aimed to take on the responsibilities of the HGC and establish schemes to prevent genetic discrimination and find solutions for the use of genetic test results in insurance. The committee was closed in 2014 after coming to the conclusion that a committee format was not the best way forward, and a more flexible approach was needed. However it is hoped that the expertise of its members would continue to feed into emerging issues around health science. 

The Food and Drug Administration (FDA) in the US is working to protect the public from any risk of harm resulting from being misled by test results that are inaccurate and not supported by clinical interpretation.  In 2009, the FDA made clear their concerns regarding a number of direct-to-consumer genetic tests. The FDA has requested concrete evidence from suppliers that the genetic results from their tests are scientifically accurate and therefore not having a negative effect on the health of their customers.

The California-based company, 23andMe, formally launched a direct-to-consumer test in the UK at the end of 2014 which has gained wide publicity. While recognising the importance of raising awareness of genomics in the UK, the Department of Health (DoH) has warned people to think carefully before buying the test as no test is 100 per cent reliable. The UK’s Medicine and Healthcare Products Regulatory Agency, which regulates medicines and medical devices in the UK, has emphasised that the tests should be used with caution. 

Interpreting risk

It's important that the people who are looking at these interpretations understand what that means

Josh

A major obstacle in the interpretation of direct-to-consumer genetic test results is mathematical ability and the interpretation of risk. For individuals interpreting genetic tests on their own it can be very difficult to have an understanding of what a one or two per cent risk means for their health. It is important to provide context for the risks described in these tests so as to not cause unnecessary anxiety if an individual finds an elevated risk.  

Direct-to-consumer genetic testing: interpreting risk

In clinical genetic testing, individuals will be advised to accept the services of a genetic counsellor or specialist to explain the implications of their test results. With direct-to-consumer tests, this may not be the case. The worry with this is that people may end up making key decisions about their health based on inaccurate or incomplete genetic information, or based on a misunderstanding of the statistics involved.  

In general however, the majority of health reports given by direct-to-consumer tests are based on very small shifts of risk which can generally be addressed by eating a healthier diet and taking more exercise. 

Privacy

Another important issue to consider with direct-to-consumer testing is the potential for personal genetic details from these tests to be shared or get into the wrong hands. What happens to your DNA once you send it to a private company? Direct-to-consumer testing companies may promise not to share confidential genetic information with third parties without customer consent. This will provide some protection but it is important to understand the detail of a company’s privacy policy before supplying DNA for testing.

Also, what happens if a company were to go out of business? This was a worry when the direct-to-consumer company deCODEme filed for bankruptcy in 2009. deCODEme had a huge database containing medical records and genetic data of all Icelanders. Therefore, when it went bust, there were huge concerns about what would happen to the data and whether the privacy of the participants would be protected. Although there were no adverse outcomes in this particular case, the uncertainty and lack of clear rules in this situation was a source of concern.

Official US government guidelines state that life and health insurers are not prohibited from using genetic test results to fairly assess the risk and price risk in the interest of all their customers.

In some countries there are laws in place, such as the Genetic Information Non-Discrimination Act (GINA) of 2008 in the USA, to help protect individuals against discrimination following genetic testing. However, these laws sometimes have loopholes. Official US government guidelines on GINA, for instance, state that life and health insurers are not prohibited from using genetic test results to fairly assess the risk and price risk in the interest of all their customers. However, it is not clear that there has been a significant impact on the insurance market as a result of genetic testing. For example, a study published in 2003 followed 636 women who had undergone testing for the BRCA1 and BRCA2 genes. It found that none of the women had life insurance denied or cancelled as a consequence of the test result. 

This page was last updated on 2016-06-13