Resources: Commercial DNA tests

HOW TO: delete your data from commercial company databases:

The following websites provide guided instructions on how your data can be deleted from a commercial DNA company’s database:

Consumer Reports: How to Delete Your Data From 23andMe, Ancestry, and Other Sites

Know Your DNA: How to Delete Your Data from every DNA testing service


Consumer Federation of America, 2020: Should you buy a Genetic Testing Kit?


Boston Review (2021): DNA and Our Twenty-First-Century Ancestors. By Professor Dauna Fullwiley. Home DNA ancestry kits include no ancestors, instead comparing customers to other present-day people based on assumptions about race and ethnicity. So what are they actually selling?


Twins get ‘mystifying’ DNA ancestry test results (Marketplace) CBC Radio-Canada
Vox (2019): What DNA ancestry tests can – and can’t – tell you
Gizmodo (2018): Consider These Risks Before You Take That Test


House of Commons Science and Technology Committee (June 2021): Direct-to-consumer genomic testing: First Report of Session 2021–22

UK government Science and Technology Committee recommends stronger regulations on consumer genetic testing.

A new report by the UK House of Commons Science and Technology Committee recommends that commercial testing companies selling direct-to-consumer tests should be properly regulated before they are put on the market, in order to ensure that they are reliable and clinically useful. New EU laws were recently introduced to require pre-market assessments of commercial tests (‘in vitro diagnostic medical device’ regulation (IVDR)). 

However, with UK exiting the EU before these new laws were implemented as a result of Brexit, England may continue with existing legislation that allows companies to self-declare if their tests are at all accurate or reliable in giving health-related information.
(Though Scotland has implied that they will continue to follow EU rules going forward, and it is likely that Northern Ireland will have to follow such laws).

Some of the issues raised in the report include the limited number of instances where genetic tests can accurately diagnose or predict disease risk. The report warns that consumers may overestimate their risk as a result of a genetic test, which may lead to unnecessary treatments or avoiding particular activities. Meanwhile others may underestimate risk due to favourable result, and thus delay seeking medical assistance. Moreover, such results may impact on people’s mental health if a disease is untreatable.  Individual accounts of harms were described, with one example of a woman considering potentially dangerous medication following results of a commercial test.

Evidence of inaccurate or misleading results are described, noting that different results were obtained when identical samples were sent to different companies, with one report citing 40 % of tests as being incorrect, and another showing that up to 80% of samples tested resulted in false-positive, incorrect results. Such inaccuracies may add unnecessary burden to the NHS who have to confirm the commercial result, only to find that a substantial number of results are incorrect. There is a lack of study currently to be able to properly estimate the burdens and costs that such tests may place on the health service, and the report recommends that information is gathered to further understanding of this issue, as well as considering the possibility that companies can contribute to any additional costs incurred by the NHS as a result of commercial testing. There is also inconsistency between companies with regard to what gene variants are tested for. Some companies will for example test for hundreds of genes for cancer, but only 15 % of genes were present across all eight companies’ testing methods, when analysed in a study. In other cases, not all genes associated with disease risk are included in tests, giving rise to the risk of false assurances.

Concerns for tests for diet and lifestyle are also raised, with one scientist’s submission describing such tests as merely ‘sexing up’ standard dietary and exercise advice to make money from people when there is no evidence that the product works. 

Privacy and consent issues are also covered, with concerns surrounding potential lack of consent when companies make broad permission requirements for ‘research and development’, or that data may be used for criminal investigations, immigration enforcement, or insurance or job applications. Further, data may be vulnerable to security risks, or transferred to other parties if ownership changes when a company is sold. Privacy issues include the ability to identify distant relatives from any individual’s data.

In light of the above concerns, the report recommends that consumer tests are independently validated in line with many of the new requirements in the new EU law, with clear standards on technical performance. Currently, there are no requirements for commercial tests to meet the standards required in other settings such as the NHS. As such, commercial test results should not be integrated in the NHS patient records. 

The report also recommends, in line with the new EU legislation, that clinical ‘utility’ is independently tested prior to any test being sold to the public. The report also recommends that claims made to costumers are accurate and not misleading. Performance requirements do not currently include the clinical performance of a test, which means that any test result does not necessarily lead to providing any useful information on diagnosis, treatment, management or prevention of a disease. As such, results might merely serve to give information on a genetic variant, which in itself may not translate to a beneficial clinical outcome. Experiences to date suggest that how important a genetic variant is considered to influence health and disease can change over time, and can even be disproven very quickly in light of new understanding. 

For a test to have good clinical utility also requires that any result is placed in the wider context of an individual’s circumstance e.g. family history and symptoms, which is needed to improve accurate interpretation of the genetic result. The NHS already takes into consideration such contextual factors, with expert supervision along with genetic counsellors provided to assist the whole testing process. Such contextual analysis is thus recommended to be incorporated as a safeguard against inaccurate commercial testing outcomes. 

Other recommendations include that specific requirements be considered with regard pre-natal testing, which may influence decisions on terminating pregnancies. Restrictions on such tests should be considered, along with tests being performed on children that do not have any symptoms of ill health. 


Phillips A (2018): Direct to Consumer Genetic Tests: analysis of contracts and list of commercial companies


BMJ (2019): Direct-to-consumer genetic testing.


Why using DNA to trace ancestry is problematic:

Mathieson I & Scally A (2020) What is Ancestry?


Position Statement on Direct to Consumer Genomic Testing by the UK Royal College of General Practitioners (2019)

Royal College of General Practitioners (RCGP) and the British Society for Genetic Medicine (BSGM) recommend that health professionals should exercise caution when asked to offer, or provide, clinical expertise about the results of Direct to Consumer (DTC) genomic or genetic testing.

The analytical validity, sensitivity and clinical utility of such testing may be much lower than is popularly perceived. For certain types of DTC results, there is a very high chance of false positive or false negative results. This means that patients should be offered the NHS care which would otherwise have been offered (e.g. family history and risk assessment, healthy lifestyle advice, or referral to specialist care)1 regardless of their DTC result.