The American Society of Human Genetics (ASHG) has asked the question, "How accurate is your family tree," questioning the accuracy of modern DNA testing, as reported in Science Magazine. According to the article, there is a building concern among geneticists and others that the tests performed, both by companies and in academic labs, may not be very accurate, largely because they match samples to "reference" populations of a particular ancestor who may or may not perfectly fit the desired profile. Although not mentioned in the article, one high profile case that comes to mind is that of talk show host, Oprah Winfrey, who stated in 2005 that DNA testing proved her to be of the Zulu tribe. However, research and further testing done as part of Winfrey's participation in the television show, "African American Lives," showed otherwise.
"Even in the best databases that exist today, we know we have only a small sampling of human genetic diversity," says Michael Bamshad, who studies genetic variation at the University of Washington, Seattle.
At its annual meeting, a 10-person ASHG committee released five recommendations that aim to bring more accuracy, oversight, and collaboration to commercial and academic ancestry testing efforts. But it's unclear what effect the recommendations will have.