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    • Freedom of HGC08/P17 Information Status OPEN HUMAN GENETICS COMMISSION Genetic Ancestry Testing Paper HGC08/P17 Purpose 1. The purpose of this paper is to provide background to a possible draft HGC statement on genetic ancestry testing (Annex A). The Commission is asked to consider the issue of genetic ancestry testing and to consider a draft HGC statement and provide comments. Commissioners are invited to consider whether HGC should respond to recent developments in this field and, if appropriate, to consider a draft HGC statement on genetic ancestry testing and to offer comments and/or amendments for the preparation of a final version. Background 2. Genetic ancestry testing is becoming increasingly popular amongst consumers seeking information about their family histories, including the geographical origins of their ancestors. 3. In February 2004, the HGC held an information-gathering meeting on the topic of DNA-based genealogy in order to gain an understanding of the current scientific basis, commercial activities and personal narratives in relation to genealogy testing. 4. In October 2007, the internet-based company ancestry.co.uk launched a DNA testing service to support its genealogy service. Many other internet- based companies offering this type of service exist in the UK and worldwide. 5. An analysis of some of the issues that are raised by genetic ancestry tests was published in Science in October 2007 (Annex B). According to this article, more than 460,000 people have purchased such tests in the past 6 years and interest in DNA-test based genealogy continues to rise. 6. In May 2008, the HGC was contacted by a senior researcher from Computing Which? preparing an article on issues relevant to DNA testing for genealogy purposes. The article was published in the July 2008 issue of Computing Which? (Annex C). 7. The main issues associated with genetic ancestry testing are its scientific constraints, the constraints this imposes on the interpretation of results, how these results are presented to the consumer and the personal impact HGC08/P17 – Page 1
    • HGC08/P17 the results might have on people taking the tests and their families, as well as certain sociological consequences. Scientific constraints of DNA ancestry testing 8. The most commonly offered analyses are Y chromosome tests and mitochondrial DNA tests. 9. Y chromosome-based genetic genealogy involves testing for short tandem repeats (STRs) and/or single nucleotide polymorphisms (SNPs). STR sequences on the Y chromosome change frequently between generations and therefore, in general, the more STRs are held in common the higher the probability of a genetic relationship. By contrast, single nucleotide polymorphisms occur with much less frequency and can therefore be indicative of a shared progenitor. Used in combination, STR and SNP analysis can provide a greater probability of common ancestry. 10. The sperm’s mitochondria are destroyed after fertilisation and mitochondrial DNA can therefore be used as an indicator of maternal ancestry. Mitochondrial DNA has a high mutation rate and genetic ancestry analysis uses DNA markers in the hypervariable region. 11. One scientific constraint is that both Y chromosome analysis and mitochondrial DNA analysis can only ever provide information about a single common ancestor, i.e. the original provider of the Y chromosome or mitochondria. It does not provide ancestral information encoded by a person’s autosomal chromosomes. 12. Similarly, for both Y-chromosome and mitochondrial DNA analysis, probable progenitor populations are identified by comparing the individual’s DNA markers with known population databases. The usefulness of the information gained from matching an individual’s DNA to a given database therefore depends on the size and sample variety of the database, which may also only include data from individuals living in a small geographical area. 13. In conclusion, any interpretation of DNA based genealogy analysis has to bear in mind the scientific constraints and the fact that any result will in most cases only provide a measure of probability of ancestry. Personal and familial issues 14. As well as trying to find out more about their historical ancestry, some people may use these services in the hope of identifying contemporary biological relatives. For example, some companies offer a facility that allows the individual to search a database for matches with other users. Whilst this may offer adopted or donor conceived people a way of finding their biological parents, it may for some also provide unexpected news of non-paternity and, for others, an unwelcome and unexpected intrusion of their privacy. HGC08/P17 – Page 2
    • HGC08/P17 15. There are also issues around data-sharing and consent. For example, the Which article quotes one company sharing both the customers’ DNA results and their name with others on the database by default, the consumer would actively have to change their privacy settings in order to opt out of the data-sharing. Sociological issues 16. DNA based genealogy is sometimes viewed as a harmless recreational activity which presents little risk to the consumer. However, this perception does not take into account the fact that many consumers use these tests in order to find out more about their individual and/or ethnic identity. Any incomplete or misguided interpretation of results therefore has the potential to affect a person deeply. In some cases where the results are unexpected or undesired, or contradict other traditions with which the individual may have identified, the results may also cause distress. 17. Other concerns about impacts are the area of social policy. If a person uses the information provided by a DNA based genealogy test as confirmed proof of their racial or ethnic identify, it may affect how they record their ethnicity on official documentation which could in turn have an impact on ethnic equality monitoring. There can be financial consequences and motives, too. In the United States, for example, the results obtained from these tests have led individuals to financially support certain communities in the developing world; others have taken the tests in order to gain access to social welfare programmes. Other issues 18. Some of the other issues associated with commercial DNA based genealogy services are the same as are relevant to other commercial DNA-based tests. They include arrangements for providing consent, quality assurance and scientific standards, sample storage conditions, and security and accessibility of the database. 19. Some anthropologists have raised additional concerns over a possible loss of consumer confidence in genetic tests and in genetic research more generally. If consumers discover that they were not adequately informed about the limitations of DNA based genealogy and perceive that they were misled, they may develop a distrust of the medical research community. Questions for discussion 20. The HGC is currently preparing further work on direct-to-consumer genetic testing. The Commission has also prepared a draft statement of support to the Scientific Advisory Committee on Nutrition’s statement on ‘nutrigenomics’ (to be discussed at this plenary, under Standing Items paper number HGC08/P19). Commissioners may therefore wish to discuss: HGC08/P17 – Page 3
    • HGC08/P17 o to what extent the issues presented by genealogy testing are distinct from those raised by direct-to-consumer genetic testing in general o whether provision of these tests in inappropriate circumstances has the potential to cause harm to the consumer o whether the issues presented by commercial DNA-based genealogy services are of enough significance that although the tests do not make health-related claims, they should be subject to some form of regulation and whether they should therefore be included in the work that HGC is planning on direct-to-consumer genetic testing o whether a statement on genetic ancestry tests should be published on the HGC’s website in advance of HGC’s further work on direct genetic testing Conclusion Commissioners are asked to consider and discuss the above questions. If it is decided to proceed with the publication of a statement on genetic ancestry testing on the HGC website, Commissioners are asked to provide comments on the draft statement attached at Annex A. HGC Secretariat September 2008 Annexes Annex A – Draft HGC statement on genetic ancestry testing Annex B – “The science and business of genetic ancestry testing” (Science, Vol 318, pp 399-400 (19 Oct 2007), available at http://www.sciencemag.org/cgi/content/short/318/5849/399 Annex C – “Genetic defect” (Computing Which?, July 2008) http://www.which.co.uk/portals/P/magazines/computing_which/co mputing_which_483_63486.jsp HGC08/P17 – Page 4
    • HGC08/P17 – ANNEX A Draft HGC Statement on Genetic Ancestry Testing Genetic ancestry testing is becoming increasingly popular amongst consumers seeking information about their family histories including the geographical origins of their ancestors. In recent years, academic anthropologists have begun to use DNA technology to study the history and structure of populations and to explore patterns of migration and human genetic diversity. Increasingly, however, genetic databases, which are compiled for purposes of studying population groups, are also being used by commercial providers offering ancestry testing for individuals. Such commercial DNA ancestry testing, in addition to having scientific limitations which require careful interpretation of results, raises a number of other issues of which consumers should be aware. On the one hand, commercial genetic ancestry testing can be seen as just one of the ways in which people try to make sense of their origins and family history – a personally rewarding recreational activity. On the other hand, if not interpreted in the right way, the results of such tests have the potential to change an individual’s perception of their identity and therefore may present more serious consequences for the individual, their relatives and for society more widely. One scientific constraint is that both Y chromosome analysis and mitochondrial DNA analysis, the most common types of test, can only ever provide information about a single common ancestor, i.e. the original provider of the Y chromosome or mitochondria. It does not provide ancestral information encoded by a person’s other (autosomal) chromosomes. Similarly, for both Y-chromosome and mitochondrial DNA analysis, probable ancestral populations are identified by comparing the individual’s DNA markers with known population databases. The usefulness of the information gained from matching an individual’s DNA to a given database therefore depends on the size and sample variety of the database, which may also only include data from individuals living in a small geographical area. Given these limitations, consumers should consider carefully their motivation for undertaking DNA-based genealogy. The results that are provided will in most cases only provide an incomplete picture of genetic ancestry. The results may also have emotional consequences, especially for people who may use them to answer fundamental questions of identity and ethnicity. Some DNA-based genealogy services offer a facility that allows the individual to search a database for matches with other users. It is important that consumers are aware of the privacy implications of such data-sharing. Whilst some results may come as a pleasant surprise, others might be unwanted and/or unexpected, for example, it may reveal that a person’s presumed parent is not their biological parent. HGC08/P17 – Page 5
    • HGC08/P17 – ANNEX A Important points to take into account, and questions to ask, when taking an ancestry test are: • There is a high level of genetic diversity within populations and little evidence of distinct biological groups. • There is not a strong relationship between an individual’s DNA and their race or ethnicity (these are social rather than biological categories). • The tests cannot accurately say which part of the world a person’s ancestors came from. • Does the company provide enough information so that the consumer can come to an informed decision on how useful/informative the test is going to be? • What is the company’s policy for storing DNA and what will happen to the results (for example, will they be publicly available and will they identify the individual)? Some of the limitations of testing and the comparisons made with other samples will diminish as more research is done. However, for the time being the puzzle of our ancestry and origins is not going to be completely solved by DNA analysis. Further reading Beware the Gene Genies – Martin Richards (Education Guardian Feb 21 2003) The Science and Business of Genetic Ancestry Testing – Bolnick et al (Science Vol 318 Oct 2007) Genes Direct (HGC, 2003) and More Genes Direct (HGC, 2007) HGC08/P17 – Page 6