The remaining 12 clusters separate the individuals of European ancestry. For ease of interpretation, we removed the samples obtained from Australia, Canada, and the US, and focus our validation on 2,302 European samples, which can be more successfully categorized by ancestry based on geographic origin. These individuals could be classified to one of the 34 European countries represented in the database (Table I). Sample sizes varied greatly across countries. Switzerland is represented by 1,014 individuals. Some countries are represented by only one subject. Seven countries had samples of size 60 or more. Countries with smaller samples were combined to create composite country groupings based on region; see Table I for definition of country groupings.
