Genetics and Racial Minorities

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GENETICS AND RACIAL MINORITIES

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Advances in genetic research such as the completion of the Human Genome Project (HGP) have significant implications for the health of members of racial minority groups. Research on human genetic variation is anticipated to increase biomedical understanding of disease etiology and affect social and cultural meanings of race. In this entry the ethical implications of genetic research for the health of members of racial minorities are discussed. Racial minorities are defined as groups that historically have been identified by race and as a result have limited access to resources and opportunities. This entry discusses the implications of advances in human genetics for the understanding of race and ethnicity and the impact of racial categories on research into human genetic variation. It addresses the effect of these implications on the national priority to decrease health disparities among racial groups in the United States. Discussion topics include genetic determinism and reification of race, the protection of research participants and informed consent, and the distribution of benefits from human genetic research and its implication for justice in regard to the health and well-being of members of racial minorities.

Human Migration, Genetic Diversity, and Race

Since its genesis in the sixteenth century, the concept of race as a biological kind has been a focal point of debate (Boxill). Controversy over the use of the term has emerged in regard to the values that have been attached to groups identified by race and the characteristics that have been attributed to them. Throughout the twentieth century scholars consistently challenged the validity of biological differences between populations that were linked to race. Scientific research consistently has revealed that more genetic variation exists within than between populations (Lewontin). Despite this finding, race has become increasingly salient in understanding disparities in the health status of population groups and continues to be an important factor in both biomedical research and clinical medicine.

Central to arguments over race is a lack of agreement on its definition. In a manner that often is implicit, biomedical researchers and clinicians use a potpourri of surrogate concepts, including skin color, hair type, national origin, and citizenship, to identify race. This situation is complicated by the common practice of relying on self-reports, which often are based on factors that have little to do with biology. In addition, racial categories change over time and tend to be context-dependent, as is illustrated by the history of U.S. Census racial and ethnic categories (Lee et al.). Since the insertion of the term race into scientific discourse, the definition of race has been a moving target, and this has contributed to confusion about its meaning and implications for biomedical research and clinical care.

In 1996 the American Association of Physical Anthropologists issued a statement that included the following assertion: "Pure races, in the sense of genetically homogenous populations, do not exist in the human species today, nor is there any evidence that they have ever existed in the past." Although it acknowledges that differences between individuals exist, the statement emphasizes that those differences are the result of hereditary factors and the effects of natural and social environments. Genetic differences between populations result from the effect of the history of human migration and reproduction and consist of a gradient of varying frequencies of all inherited traits, including those that are environmentally malleable.

Critical to comprehending human genetic variation is an understanding of the meaning of population genetic structure, which is best understood as the pattern of genetic differences among genomes, the full sets of human genes found in the nucleus of each cell. These genes are arranged linearly on chromosomes and consist of strings of chemical units called nucleotides (Weiss). The genome interacts with the environment to produce phenotypes, or all observable traits of individual appearance and behavior. Patterns within the genome vary across a species, depending on the history of mating within that species. The patterns or genetic frequencies of human populations have been affected by mutation, migration, natural selection, and random genetic drift to varying extents. These forces have resulted in the genetic variation that exists among human populations. Genetic differences between global populations do not map neatly onto the racial categories that have emerged through sociohistorical processes. Instead, race, defined by discrete group boundaries, serves as a poor proxy for the continuum of human genetic variation.

Racial Categorization in Human Genetic Variation Research

The completion of the HGP has resulted in new and well-funded themes of scientific inquiry in medicine. A central goal of human genetic research is identifying the genetic and environmental causes of human disease. Recent advances such as high-throughput genomic sequencing technology have increased the efficiency of large-scale rapid genotyping and ushered in a new era of genetic epidemiological research. This research has focused on the identification of single-nucleotide polymorphisms (SNPs). As was discussed briefly above, the genome is specified by the four nucleotide "letters" A (adenine), C (cytosine), T (thymine), and G (guanine) that form patterns. SNP variation occurs when a single nucleotide, such as an A, replaces one of the other three nucleotide letters: C, G, or T. SNPs are believed to be associated with individual differences in susceptibility to disease; environmental insults such as bacteria, viruses, toxins, and chemicals; and drugs and other therapies.

The search for these genetic clues has led to efforts to map SNPs and use that information to identify the multiple genes associated with complex diseases such as cancer, diabetes, vascular disease, and some forms of mental illness. For most SNPs, all populations have all the possible genotypes for a SNP, but populations may differ in regard to the frequencies of individuals with each of the different genotypes.

Although the location of SNPs is believed to hold the key to identifying the genetic basis for the onset of disease and influencing responses to drug therapeutics, it has been posited that SNPs do not travel independently. Instead, SNPs are located in what has been identified as blocks of alleles that are inherited as units. The patterns of the SNP alleles in those blocks are called haplotypes. Studies show that most SNPs are in haplotype blocks that have been transmitted for many generations without recombination. Because each block has only a few common haplotypes, identifying haplotypes eliminates much of the tedious work of attempting to find single SNPs that are correlated meaningfully with disease. In effect, the task of locating frequently elusive needles in the enormous haystack of the human genome has been mitigated by the knowledge that these needles, or SNPs, tend to be located in groups. It is expected that the 10 million common SNPs will be reduced to 200,00 to 300,000 tag SNPs that will signal the location of regions that affect disease more readily through genome scans.

To create a genetic test that will screen for a disease in which the disease-causing gene already has been identified, scientists collect blood samples from a group of individuals affected by the disease and analyze their DNA for SNP patterns. Next, researchers compare those patterns to patterns obtained by analyzing the DNA from a group of individuals not affected by the disease. This type of comparison, which is called a disease gene association study, can detect differences between the SNP patterns of the two groups, indicating which pattern most likely is associated with the disease-causing gene. Eventually, SNP profiles that are characteristic of a variety of diseases will be established. As part of that effort an increasing amount of research has called for the DNA sampling of individuals identified with specific racial minority populations. The collection of DNA samples has resulted in the racial categorization of genetic material stored in governmental and commercial genetic databases.

Scientific Racism and Eugenics: Cautionary Tales

In considering the ethical implications of race in human genetics research, it is prudent to review the lessons learned from the history of scientific racism in medicine. In the United States and abroad scientific racism has resulted in the exploitation of racially identified populations in the name of scientific and medical progress. Although science often has been portrayed as value-free, scientific theories have been used to support beliefs in the inferiority of racialized populations. Historically, race began as a biological taxonomy by which humans were categorized according to phenotypic differences such as skin color and facial features and by supposed personality traits. Despite general rejection of such definitions, scientific research is at times compromised by a priori assumptions that build on notions of race as biology.

The term eugenics, which was coined by Francis Galton early in the twentieth century, has been incorporated into various state-sponsored programs around the world (Galton). The most notorious of those programs was guided by the German program of Rassenhygiene, or "racial hygiene," that led ultimately to the Holocaust. In the early 1900s the eugenics program was promoted through scientific organizations such as the Society for Racial Hygiene and the Kaiser Wilhelm Institute for Anthropology, Human Genetics and Eugenics. Later, when incorporated into Nazi ideology after the rise of Adolph Hitler, the racial hygiene program led to a broad spectrum of egregious scientific experimentation and the eventual extermination of millions of Jews, Gypsies, homosexuals, and other individuals deemed undesirable by the Third Reich (Weigmann).

During that period of state-sponsored racism, other nations, such as Great Britain, Norway, and France, were adopting their own brands of eugenics policies. Eugenics gave scientific authority to social fears and lent respectability to racial doctrines. Powered by the prestige of science, it was coupled with modernizing national projects that promoted claims of social order as objective statements grounded in the laws of nature (Dikotter). Unfortunately, history provides several examples of how the marriage of scientific racism and national political agendas has led to the unfair treatment of socially and politically vulnerable racial minorities. In South America, for example, eugenic policies have been the key to a national revival in which indigenous concerns over racially diverse and socially disparate societies have led to race-based initiatives to regulate human reproduction. Brazil and Argentina have experienced the use of science in the name of forging "superior and cosmic national races" (Stepans).

Perhaps the longest single study involving the exploitation of human subjects in medical research was the Tuskegee Syphilis Study conducted by the U.S. Public Health Service. The study, which was called the Tuskegee Study of Untreated Syphilis in the Negro Male, began in 1932 and did not end until 1972. The study involved the recruitment of over 300 black men with syphilis who were told by researchers that they were being treated for "bad blood," a local term used to describe several ailments, including syphilis, anemia, and fatigue (Jones). Those men did not receive proper treatment even after penicillin became available as an effective therapy in 1943. In exchange for taking part in the study, the men received free medical examinations, free meals, and burial insurance. The Tuskegee Study caused a public outcry that led the assistant secretary for health and scientific affairs to appoint an Ad Hoc Advisory Panel that concluded that the Tuskegee Study was "ethically unjustified" (Brandt). It is a "powerful metaphor that has come to symbolize racism in medicine" (Gamble) and a cautionary tale about the vulnerability of racial minorities in biomedical research.

Ethical Issues of Identifying Race in Genetics

The development of genomic research technologies has the potential for a dramatic enhancement of biomedical prevention and treatment of disease. Efforts to identify genetic mutations associated with disease may yield significant findings that uncover important clues to the onset of common diseases. Critical to these endeavors is a growing need to understand human genetic variation. In the absence of cost-effective ubiquitous genotyping technology, researchers have tended to favor population-based sampling. Strategies of using racially identified populations in the mapping of genetic markers, however, should be viewed with due consideration of the potential ethical implications of such research. Of particular concern are the potential for stigmatization and discrimination, informed consent, and distributive justice.

REIFICATION OF RACE: STIGMATIZATION AND DISCRIMINATION. Historically, race, genetics, and disease have been linked inextricably, producing a calculus of risk. Sometimes these associations are accurate, and sometimes they reflect underlying social prejudice. One risk in medical research is that any racial or ethnic identifiers used in human genetic variation research will come to be reified as biological constructs, fostering a genetic essentialism. This essentialism could obscure the fluid nature of the boundaries between groups and the common genetic variation within all groups.

An example is sickle-cell anemia, an autosomal recessive disease that is caused by a point mutation in the hemoglobin beta gene (HBB). It is a condition that has been racialized as a "black disease" in the United States. However, closer scrutiny reveals that the incidence of sickle-cell anemia is associated with zones of high malaria incidence, because carriers of that gene have some degree of protection against malaria. The condition is the result of human migration and the interaction of genes with the environment. Its emergence as a racial disease is an artifact of U.S. history. If the source of slaves to the Americas had been Mediterranean regions, where the incidence of the disease is also appreciably high, rather than from Africa, sickle-cell disease might have become known as a southern European disease. The reification of race results in such conflations.

Stigma and discrimination are potentially harmful consequences that are associated with the reification of race and genetic essentialism, particularly if curative measures are not available. Insurance companies and managed-care organizations in particular have an economic stake in controlling the potential costs of "high-risk" clients (Knoppers). In addition, social prejudice could arise in the identification of correlations between genes and disease. Race may be treated as an independent variable in the calculus of risk and result in real social harms for individuals in regard to the anticipation that they will fall ill.

INFORMED CONSENT: PROTECTING POPULATIONS. Harm from race-based genetic research may extend beyond the individuals at risk for a particular disease if targeted genetic testing implicates socially identifiable groups. Increasing attention to the ethical implications of research on human genetic variation has resulted in a shift of emphasis from individuals to "groups." The question of who should "consent" to genomic research demands a discussion of who are the potential victims of research-related harms (Kass and Sugarman). Although the informed consent process focuses on individual participants in scientific studies, risks stemming from population-based research may affect those who are not direct participants but are implicated by their identification with particular groups (Wilcox et al.; Faden and Beauchamp).

Acknowledgment of such harms has fueled a growing debate over whether individuals alone are sufficient to consent to research participation or whether others who subscribe to or are ascribed membership in a racial group also should participate in this process as potential victims of research (Greely). Several scholars and policy makers have advocated "community consultation," arguing that internal review boards (IRBs) should implement new mechanisms that supplement individual consent with group permission (Weijer; Foster and Sharp; Clayton). Others have countered that giving groups the moral authority to bestow informed consent is conceptually flawed and logistically confusing (Juengst). In dispute are the assumptions that (1) there is a singular, self-evident social body that represents a particular individual human subject, (2) that social body has the moral authority to speak for all the members of a particular group, and (3) consultation with that social body absolves researchers of responsibility for prospective harms.

Population-based DNA sampling and the identification of racial minorities in research on human genetic variation have broadened the debate over informed consent. At issue are the responsibilities of researchers and clinicians for preventing future harms associated with knowledge that links race, disease, and genes and the need for the participation of research populations in the scientific process.

DISTRIBUTIVE JUSTICE: THE PROMISE OF PERSONALIZED MEDICINE. The decision to identify race in human genetic research may have important ramifications for the establishment of research priorities that could have implications for helping exacerbate or ameliorate health disparities between groups. An example of such research is the field of pharmacogenomics. It is well recognized that most drug therapies exhibit wide variability among individuals in terms of efficacy and toxicity. It has been estimated that over 100,000 patients die and 2.2 million are injured annually by adverse drug reactions (Lazarou et al.). For many medications differences in reactions are due in part to SNPs in gene-coding drug-metabolizing enzymes, drug transporters, and/or drug targets. The ultimate goal of such research is to develop "individualized" drug therapy that will reduce adverse side effects and provide cost-effective medicines (March et al.)

The adoption of pharmcogenomics has serious implications for the practice of clinical medicine. The populationbased approach to the marketing of healthcare products raises the possibility that drug development will build on and strengthen notions of racial difference. Furthermore, racial thinking may have ramifications for the perceived beneficiaries of pharmacogenomics research in that racially identified consumer groups may unduly dictate the scientific development of therapeutics. This may lead to a racial segmentation of the market in which drugs are directed at groups in a way that will increase the economic health of the companies investing in therapeutics.

In the unlikely event that genotyping becomes so common that patients are able to identify themselves in terms of the multitude of SNPs involved in disease gene associations and drug metabolism, human genetic variation research will continue to use racially identified populations. Genetic research offers the potential for significant progress toward the mitigation of health disparities between populations in the United States. However, history serves as an important reminder that every leap in scientific advancement must be tempered by careful consideration of its ethical implications.

sandra soo-jin lee

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