One of the motivations for this kind of work is to assist genetic epidemiology, or population-wide genetic studies. Indeed, this is one of the main goals of Glaxo Smith-Kline, which participates in the study, says Novembre. “They are interested in pharmacogenetic purposes to do case control studies of adverse drug reactions,” he says.
“The idea is to save money in these large-scale genetic epidemiological studies,” says Krawczak. “It’s very costly to genotype people.” But if you can create genetic control groups for distinct populations, it allows you to more easily test drugs against different populations to see where the benefits lie, he says.
At the moment, the main focus is on Europe because it has a lot of genetic variation but a relatively well defined and delineated history. “It’s a nightmare to do population genetics in America,” says Krawczak. “There are so many migrant populations from different parts of the world that it’s just too complex.”
Even so, Novembre says that he plans to extend this sort of research to cover larger parts of the world and individuals of mixed ancestry. “At the moment, if you have mixed grandparent ancestry you appear between the set of countries where the grandparents come from,” he says. “So if they are part Italian and part British, they would appear in Switzerland. But we are working on algorithms that will be able to infer grandparent ancestry and get around this.”
Eventually, this sort of research is likely to be picked up by the growing number of companies offering DNA home tests over the Internet to people wishing to trace their genealogy. At the moment, these services tend to offer fairly rough pictures of one’s origins. But as the microarray technology becomes cheaper and the statistical software used to map it becomes more sophisticated, these kinds of services should greatly improve, Novembre says.