Over the last 20 years, researchers have made huge steps in understanding the relationship between genes, environment and complex traits. While these advances are heralded as leading to a future of improved health outcomes, individuals of minority descent are underrepresented in genetic research and thus are unlikely to benefit equally from advances in genetics.
In an article published by the American Journal on Addictions, COBE Director Dr. Danielle Dick explores the limitations of existing data sets used in genetic research, the importance of diversity within those data sets and possible reasons for underrepresentation of minority populations in research.
“In general, most non-white populations have been underrepresented in genetic research,” Dr. Dick said. “Some of the concerns we reviewed are applicable more broadly to underrepresented groups, while other considerations pertain to African American populations specifically.”
Genetic analysis pertaining to alcohol often begins by studying twins. With twins, researchers can figure out how much of the variation in an outcome is due to genetic influences and/or environmental influences.
Twin studies generally use data from national population registries, such as those in Sweden and Finland. While Scandinavian countries happen to be the ones with registries, their populations are very homogeneous. Thus their registries are very homogeneous as well.
The limited number of studies that have included African American twins found both similarities and differences compared to their European counterparts. Environmental influences in particular vary widely based on experiences of socio-economic status, employment opportunities and other lived experiences tied to race.
Efforts have been made to create African American specific twin registries to counteract the imbalance of current data sets, but there is still a lot of work to be done to improve the diversity of twin registries.
And it’s not just twin studies either. Individuals of African descent have also been underrepresented in gene identification efforts.
“Discussions about race and genetics are further complicated by confusion about how best to reconcile the concept of race as a social construct with the biological differences that are discussed in genetics across racial groups,” Dick said. “Socially-defined racial categories do not necessarily reflect human genetic variation; however, racial categories may be correlated with differences in ancestral history, which can lead to genetic variation across groups.”
For example, people of African descent have greater genetic diversity than Europeans based on their ancestral history. So in addition to not serving minority populations when they are not adequately represented in research, failure to include African Americans in particular could lead to important genetic variants being missed.
While it is obvious that efforts need to be made to close the research gap, they must include awareness of the history of abuses of minorities in medical research and the ethical, legal and social implications of genetic research as a whole.
“Involving individuals of diverse ancestry in discussions about genetic research will be critical to ensure that all populations benefit equally from genetic advances,” Dick said. “The best way this can be accomplished is through interdisciplinary and collaborative work with persons of diverse ancestry.”