By: Dr. Robert Gorkin
Blog Category: Race & Healthcare
In a fascinating report, Ken Batai and Rick A. Kittles critically review the use of the notion of race as a variable to categorize participants in biomedical research given the recent advances in human molecular genetics. They conclude that classifications using skin color, or self-identification with a racial or ethic (SIRE) group do not yield genetically meaningful categories. Indeed, using such traditional racial classifications can be a confounding variable.
Modern evolutionary genetics, including data from the Human Genome Project, gives strong support to the idea that Homo sapiens originated in Africa and later migrated into the other continents. Once established, these geographically and genetically isolated populations continued to undergo genetic divergence. However, since DNA tends to be conserved, the genome contains a number of ancestry informative markers (AIM’s).
Volumes of data belie the idea that molecular genetics provides an underlying biological reality (at the DNA sequence level) that validates the notion of race. In fact, the genetic variability within racially defined groups is often far greater than that separating the races. The problem occurs because the term “race” carries substantial cultural and social meanings, but has no clear biological meaning. The American Sociological Association and the American Association of Anthropologists both concur with this viewpoint. Furthermore, the sociopolitical meaning of the term can change over time. “For example, the U.S. Bureau of the Census used eight categories of racial groups in 1890, five in 1900, seven in 1950 and by 1990, the list had grown to 16 different choices.”
Nevertheless, certain AIM’s are able to give researchers reliable genetic information about an individual’s continent of origin. However, SIRE’s for African-Americans do not seem to accurately reflect this genetic information. For example, one study showed that only 34% of SIRE African-American’s possessed more than 90% West-African AIM’s.
The bottom line here is that SIRE’s are not necessarily good proxies for the genetic makeup of an individual. The authors recommend using AIM’s to accurately assess the individual ancestry of subjects enrolled in biomedical studies to unravel the genetics of disease. Pharmacogenetic studies of effect of genes on the metabolism and action of drugs are another arena where individual ancestry assessments would be superior to traditional racial classifications.
 Ken Batai & Rick A. Kittles, Race, Genetic Ancestry, and Health, 5 Race & Soc. Probs. 81-87 (2013).
 Id. at 83 (citation omitted).