Race and human disease are two issues in which genetics and culture play critical and inextricably linked roles. Moreover, research on racial disparities in complex disease is a central focus of the current debate on human genetic variation. This project will investigate the genetic underpinnings of race and disease within a biocultural context. The question driving the research is why African Americans suffer an increased prevalence of hypertension. This is a key test case since people of the African Diaspora suffer disproportionately from a number of complex diseases, which some researchers attribute to a fundamental genetic commonality. However, this view is problematic because of difficulties in defining racial groups and because it minimizes environmental influences on complex disease. This project adds a genetic component to ongoing research to test social and cultural factors involved in hypertension and stress-related phenotypes in African-Americans. DNA samples will be collected from 350 African American individuals and those samples will be assayed for ancestry informative genetic markers (for an estimate of genetic ancestry) and for candidate genes involved in hypertension and related phenotypes. Three sets of questions will be addressed: 1) What are the associations between different measures of race? 2) What association exists between genetic ancestry and hypertension? 3) Are associations between candidate gene polymorphisms and hypertension modified when ancestry, measures of skin color, and novel sociocultural data, such as personal social networks, are added to the model?
The proposed research is a unique biocultural investigation of race and human disease in which the genetic and cultural components are addressed with equal rigor. Racial inequalities in health are among the most hotly debated issues in science. Often the debate is framed in terms of an opposition between genetic and sociocultural factors, when it is more realistic to posit that that there are complex interactions between genetic and sociocultural factors. However, few studies are able to test the independent contributions of genetic and sociocultural factors because ?race? is often used uncritically as a proxy for unspecified genetic, physiologic, behavioral, or sociocultural factors. Thus, this research has the potential to dramatically transform the ways in which we think of race, self-identity and health, and the ways in which we study these phenomena.