Genome-Wide Association Studies, Alzheimer Disease, and Understudied Populations

Genetics researchers have been grappling for decades with the problem of how to identify the genetic variants contributing to disease traits with complex inheritance. In common diseases such as type 2 diabetes, cardiovascular disease, and late-onset Alzheimer disease (LOAD), a contribution by genetic variants can be inferred because these diseases are �familial�; ie, the more genetically related a relative is to the affected person, the more frequently the relative is also affected.