In the statistical study of human disease, such factors as age, sex, and race need explicit evaluation. Of these, the racial factor perhaps has been the most frequently neglected and misinterpreted. That this may prevent the more complete understanding of disease has been pointed out in a recent review1 on this subject with particular reference to the cardiovascular system.
In the evaluation of the racial factor in disease, a scientific point of departure is mandatory. This lies not in the color of the skin but in the genetic background reflected in this skin color as well as in other factors. Racial features such as pigmentation provide a basis for grouping, selection, and propagation of certain underlying genetic characteristics. It is on the characteristic genetic foundation, then, that racial differences in the interactions and expressions of disease processes become possible. The disease may be the same, but the somatic substrate