In the 19th and early 20th century, any and all observed racial disparities in health were presumed to reflect biological differences between racial groups.2 This view has been shown to be problematic. Human genetic variation, including the genetic characteristics that are of interest to health researchers and clinicians, does not naturally aggregate into subgroups that match our racial categories.3, 123 It follows that any population categorization system is arbitrary and our racial categories fail to provide good sensitivity and specificity for the presence of specific genetic variants.123 Moreover, genetic diseases that vary across population groups are rare and single gene disorders such as cystic fibrosis, Tay-Sachs disease and sickle cell that are cited as examples of the contribution of genetics to racial health disparities do not vary by continent of origin.123
