The American Society of Human Genetics Releases Statement on Genetic Ancestry Testing at 58th Annual MeetingASHG Statement Provides Framework for Understanding the Issues andImplications, Includes Recommendations Regarding Ancestry Assessment
BETHESDA, MD - November 6, 2008 - This year, an estimated half-million Americans will purchase genetic ancestry tests at costs ranging from $100 to nearly $1,000 per test. With the growing popularity of direct-to-consumer (DTC) genetic testing, it is imperative to explore the complex relationship between genetics, ancestry and race that can complicate the interpretation of these types of tests and their results. Ancestry estimation can have enormous value in human genetics research, revealing patterns of past human migration and providing a background pattern of human genetic variation, but it is often imprecisely defined and identified. In addition, any individuals are interested in using genetic ancestry testing to confirm or extend their knowledge of family genealogy, but current limitations regarding the accuracy, appropriate interpretation, and opportunity for harm associated with misinterpretation of the data, must be acknowledged.
Those who undergo ancestry testing often do not realize that the tests are probabilistic and can reach incorrect conclusions, causing emotional distress if test results are unexpected or undesired. Consumers frequently purchase these tests to learn about their race or ethnicity, yet there is no clear-cut connection between an individual's DNA and racial affiliation. These tests are also being referenced in medical settings as the public becomes more aware of the association between ancestry and disease. Patients may ask doctors to take their ancestry tests into consideration when making medical decisions, although the results are often inconclusive.
A recent ASHG statement on DTC genetic testing acknowledged the prominence of commercial ancestry testing, but focused explicitly on tests that make health-related claims or that directly affect health care decision making. However, the Society believes that ancestry testing warrants independent consideration for the following reasons:
Members of the ASHG Ancestry Testing Task Force Committee, including current president Aravinda Chakravarti, Ph.D., and president-elect, Edward McCabe, M.D., Ph.D., will unveil the Society's ancestry testing recommendations in a press briefing session at the ASHG 58th Annual Meeting in Philadelphia on Thursday, November 13, 2008. (See press briefing session and webcast details below.)
"The applications and uses of ancestry assessment are quite different when implemented for the purposes of scientific research on population genetics, versus the commercial applications of this type of test as a service that individual consumers can purchase to learn more information about the ethnic and geographical origins of their ancestors," said ASHG President Aravinda Chakravarti, Ph.D., an expert in population genetics at Johns Hopkins University School of Medicine.
"The distinction between the different applications of ancestry assessment can be a source of confusion and misunderstanding for both consumers and researchers," Chakravarti explained. "However, ASHG believes it is extremely important that the scientific research community, industry and the public understand the limitations, risks and benefits involved."
For consumers, personal decisions about ancestry testing may ultimately depend on the cost and type of genetic markers used in the test, as well as the specificity of the information that the test results are designed to provide. The ASHG statement cautions consumers that they need to be aware of and informed about the practical limitations in the accuracy of ancestry test results. According to the statement, the accuracy of this type of testing greatly depends on the context and statistical methods used to perform ancestry estimation, regardless of the type of marker systems utilized.**
Furthermore, the terms "race" and "ethnicity" are typically used to categorize the human population into separate subgroups may be intertwined with ancestral origins, and these delineations are sometimes considered to be a key determinant of disease risk. However, it is unclear whether race may be associated with disease susceptibility due to biological or genetic factors, or whether such associations exist because these features result from environmental factors. Many researchers believe that different combinations of both genetic and environmental factors play a role in influencing human disease risk. Thus, although there are circumstances in which the genetic factors influencing health-related traits do tend to vary among racial groups, it is unclear whether (and to what extent) such risk factors account for variation in the prevalence or direct causation of these traits among different subgroups of the population.
While some challenges in research-related ancestry testing overlap with individual and commercial ancestry testing, certain issues become highlighted in the consumer testing world. For some groups (certain Native American tribes, for example), a major concern about scientific and commercial efforts to explain ancestral origins is the apparent lack of regard for important cultural, religious, social, historical and political processes that also inform group origin, membership, identity, and access to group rights. The reshaping of individual or group identity can elicit a range of psychological responses, and may result in confusion or distress, especially in the situation of conflicting information.
ASHG Ancestry Testing Recommendations:
The Society's ancestry testing recommendations for the scientific community, industry, consumers, and the general public include the following:
1. Greater efforts are needed on the part of both industry and academia to make the limitations of ancestry testing estimation more
clear to consumers, the scientific community, and the public at large. In turn, the public (consumers, in particular) have a responsibility to avail themselves of information about ancestry testing and strive to better understand the implications and limitations of these tests.
"In writing this statement, a guiding principle of our work has been that people have an intrinsic interest in their ancestry, and the human genetics community encourages this interest, as we celebrate the diversity among us," said Charmaine Royal, Ph.D., co-chair of the ASHG Task Force Committee. "However, the desire to learn about ancestry should be coupled with a drive to understand the subtleties of the problem."
"Consumers, as well as scientists, must remember that ancestry testing inferences are fallible, and that over-interpretation or misinterpretation can happen," cautions Edward McCabe, M.D., Ph.D., president-elect of ASHG. "Inaccurate results may be confusing and life-changing, therefore greater efforts are needed to make the limitations of ancestry testing more explicit."
If you would like to receive an embargoed copy of the ASHG ancestry testing statement summary paper written by the ASHG Task Force Committee, you must send an e-mail with your request to Kristen Long at , and remember to include your contact information. Please note that embargoed copies of the full-text statement will only be sent out to media contacts who have requested to receive this information. Also, please note that the summary paper will only be made available to the press after the statement has been approved by the ASHG Board of Directors. Therefore, the final version will be sent to contacts on ASHG's press list on (but not before) Tuesday, November 11.
Please direct all media inquiries to Kristen Long, ASHG Communications Manager, via , or by phone at 301-634-7346 (o) or at 240-281-2386 (c). For all onsite media inquiries during the ASHG 2008 meeting, Ms. Long can be reached via cell phone at 240-281-2386.
ABOUT THE AMERICAN SOCIETY OF HUMAN GENETICS
Founded in 1948, The American Society of Human Genetics (ASHG) is the primary professional membership organization for human genetics specialists worldwide. The nearly 8,000 members of ASHG include researchers, academicians, clinicians, laboratory practice professionals, genetic counselors, nurses and others involved in or with a special interest in human genetics.
The Society's mission is to serve research scientists, health professionals and the public by providing forums to:
For more information about ASHG, please visit http://www.ashg.org/.