At the same time, researchers found that tiny differences in DNA can provide enough information to identify the geographic ancestry of individual men and women.
The results of the Dec. 20.Science study the largest of its kind to date have implications for understanding ancient human migrations and for resolving the ongoing debate about the use of ancestry information in medical research, said Marcus W. Feldman, the Burnet C. and Mildred Finley Wohlford Professor in Stanford's School of Humanities and Sciences. Feldman led the international study, which included scientists from the United States, France and Russia.
"Different populations experience different rates of various diseases," Feldman explained. "To determine if someone is genetically susceptible to a particular disease, doctors will sometimes ask a patient, 'What is your ancestry?' But recent studies have raised the question of whether self-reported ancestry is a useful diagnostic tool, or whether it should be abandoned in favor of genetic testing."
The authors concluded that a patient interview can, in fact, provide a useful, less invasive alternative for assessing individual disease risks.
DNA "microsatellites"
In their study, Feldman and his colleagues analyzed DNA samples obtained from 1,056 people from 52 populations in five major geographic regions of the world: Africa, Eurasia (Europe, the Middle East, Central and South Asia), East Asia, Oceania and the Americas.
To identify specific populations, the research team looked for "microsatellites" short segments of human DNA that occur in specific patterns, which are passed
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Contact: Mark Shwartz
mshwartz@stanford.edu
650-723-9296
Stanford University
19-Dec-2002