Deconstructing the relationship between genetics and race

Key Points Highlighting genetic differences among people could unfortunately reinforce stereotypical features of populations, but exploring the genetic influence on common health-related traits and disparities could also be beneficial to human health. Accurate inference of an individual's ancestry using genetic data depends on several factors, including the number of genotypes used, the degree of differentiation among groups and how each group is sampled. Inferences of human population structure based on genetic data often differ from inferences based on phenotypic characteristics. Although there might be little variation among groups, it is highly structured and therefore useful for distinguishing groups and allocating individuals into groups. Insofar as geographical ancestry corresponds to some notions of race, patterns of genetic variation will also co-vary with these notions. The inaccurate measure of ancestry afforded by proxies of genetic relationships such as race or ethnicity can sometimes be useful, but in other circumstances, might lower the chances of findings disease-susceptibility loci and lessen the predictive value of clinical inferences. The success of many strategies for finding genetic variants that underlie complex traits depends on how genetic variation is distributed among human populations. This realization has intensified the investigation of genetic differences among groups, which are often defined by commonly used racial labels. Some scientists argue that race is an adequate proxy of ancestry, whereas others claim that race belies how genetic variation is apportioned. Resolving this controversy depends on understanding the complicated relationship between race, ancestry and the demographic history of humans. Recent discoveries are helping us to deconstruct this relationship, and provide better guidance to scientists and policy makers.