Health disparities among populations within the United States are well documented. In order to eliminate these disparities, we must further understand their sources. Are they the result of the unequal distribution of resources, racism, or inherent characteristics of ethnically or "racially" defined groups? How we define and discuss "race" has major scientific and moral consequences. In this issue, Leslie Klein Hoffman asks two major questions as they pertain to research on ethnic or "racially" defined groups. When is genetic research on a population appropriate? How should researchers define a given population? These questions are timely, and it is both humbling and instructive that the answers to these questions remain unclear.
Ms. Hoffman’s questions are important for two reasons. First, with its recent Health Disparities Initiative, the US government adopted the goal of eliminating health inequality among racially and ethnically defined populations by the year 2010. Second, the completion of sequencing the human genome and the intersection of genomics and medicine has the potential to transform all areas of medicine from the etiology, prevention, diagnosis, and treatment of diseases to the development of designer drugs (pharmacogenomics). How we act on the answers to Ms. Hoffman’s questions will either help bring about the changes needed to transform medicine and eliminate health inequalities, or it will strengthen the reification of "race" and "racialized" diseases.
Ms. Hoffman presents issues related to terminology and genetic literacy that exemplify the consequences of associating a disease with an identifiable population (ie, racialized diseases). When one considers breast cancer and BRCA1 and BRCA2 mutations, thoughts of Ashkenazi Jews are evoked. The association of BRCA1 and BRCA2 mutations with the Ashkenazi population was an unintended consequence of research designs and the translation of results to the general public. The favored research design had the advantage of finding the mutations among a relatively genetically homogeneous populationAshkenazi Jewswhich was possible due to a founder’s effect, and the hereditary mutations were found by ascertaining probands with a positive family history and then family members.
The results illustrate that the susceptibility alleles were segregating in some high-risk families, which denotes lineages and not "racial" genotypes. Breast cancer susceptibility alleles are not specific to Ashkenazi Jews, and Ms. Hoffman shows that despite the good intentions of the researchers, there were some negative outcomes that should be addressed.
Research in Specific Populations
Why should we perform cancer genetics research within specific identifiable populations? The answer is quite simple. Some populations may be more informative because of a higher prevalence and the higher risk of relatives of affected individuals. Also, genetic consequences of the history of certain populations may make them advantageous for finding susceptibility genes. When is genetic research on a population appropriate? This varies, but one can justify doing cancer genetic research in populations where there is an increased incidence, progression, and/or mortality suggestive of a strong genetic contribution.