Limitations of DNA ancestry tests exposed
An increasing number of people are using commercial genetic tests to look into their ancestry. However, these tests can have important limitations according to Deborah Bolnick, assistant professor of anthropology at The University of Texas at Austin. In a recent article published in the prestigious journal Science Bolnick and a team of researchers from different American universities urge the scientific community to warn the public about the problems and limitations of commercial tests, and warn consumers to use caution on these tests.
Several companies sell genetic ancestry tests which ragne between $100 and $900. These tests are intended to help people find out the origins of their ancestors. Almost half a million tests have been sold during the past six years and public interest is steadily growing.
The article argues that the tests make assumptions that lead to misleading practices that reinforce misconceptions.
Some problems and limitations mentioned in the article are that most of the tests analyze a small part of the DNA and look for only a few ancestors. The tests cannot identify every group around the worls in the way they are designed. False negative and positive results can be reported. The connection between the genetic constitution and the ethnic identity is not very clear in some cases, making it difficult to make accurate conclusions. Also, databases are incomplete, and the geographic location of the ancestors cannot be ascertained with precision.
Consumers usually have important reasons to take these ancestry tests and should be warned about possible discrepancies between the interpretations made by the company and other data such as immigration records and other sources of historic information. Companies selling these kits have to make clear to the public these limitations.
Adapted from http://www.eurekalert.org
