Medical professionals have long known that biogeographical data is useful in screening for disease risk and drug sensitivity associated with certain ethnic groups. Using a database of worldwide populations, investigators developed a dataset of reference populations that are genetically diverse and have been geographically localized for centuries. With the newly-developed tool, the investigators were able to take unknown samples, identify the proportions of admixture–meaning, genetic characteristics specific to certain ethnic groups that were combined because of events like migration or invasion–and then calculate the distance to the nearest known population that shares the same admixture signature, in order to identify place of origin.
In ethnically diverse regions, such as the U.S., where many people know only a few generations of their ancestors, this kind of screening has important medical implications. Discovery of a certain genotype might indicate the potential for a genetic disease and suggest that diagnostic testing be done. Also, as scientists learn more about personalized medicine, there is evidence that specific genotypes respond differently to medications—making this information potentially useful when selecting the most effective therapy and appropriate dosing.
You can read more in an article in the Science Codex web site at http://goo.gl/pnb8rO.