Genetic diversity also requires special attention by investigators to avoid the reporting of erroneous findings and to increase replication. Better methods for determining more homogenous population groups are required, given the rates of admixture among the U.S. population. While self-reported race/ethnicity provides a degree of accuracy of genetic homogeneity, this self-identification also includes considerable information about social factors and related environmental exposures. More precision in determining ancestral groups is, therefore, required as larger samples sizes and the inclusion of underrepresented racial/ethnic groups inevitably leads to samples characterized by greater genetic and environmental diversity. The use of PCA approaches and external reference panels to define ancestry groups does seem to provide an increase in accuracy and to improve the retention of markers and subjects. Investigators should also consider the strengths and limitations of other methods of analysis for admixed genetic data (e.g., Thornton and Bermejo15), and new approaches are sure to be developed.
