On May 31, 2006, Diverse Online published a story titled “Racial Pill Maker’s Sales Drop in Wider-than-expected Loss” about lackluster sales of the drug BiDil. The article claimed that BiDil, the heart-failure drug approved only for Black patients, is expected to usher in the era of personalized medicine. The article also implies that racial and personalized medicine are equivalent. However, they are not the same concepts, and continued confusion on this issue distracts us from the task of adequately addressing health disparities.
First, humans do not have biological races. Physical traits don’t partition individuals or populations into groups that match our social categories. Examining protein variation does not result in racial groupings either. Large-scale studies of human DNA variants reveal population subdivision (FST) values that range between 0.05 and 0.15 across the entire genome. These are values far below what biologists consider the threshold for establishing racial differentiation (FST = 0.250.)
The only approach that sometimes partitions individuals into groups similar to lay conceptions of race is non-coding DNA. This happens when you use a large number of genetic markers and is similar to forensic DNA typing in that these markers are powerful clues to ancestry. Coding portions of DNA, however, doesn’t strongly identify racial groups. This is crucial since the coding portions produce the cellular proteins that predispose us to disease and give us the ability to metabolize particular drugs. For example, a 14,400 nucleotide sequence of the gene angiotensinogen (AGT) obtained from 368 individuals of African, European and East Asian origin, did not show “racial” clustering.2 Another study examined Histocompatibility Locus A and sequenced individuals from the Republic of Macedonia and Greece. The Macedonians were more similar to an “older” set of Mediterranean populations and the Greeks were closer to Ethiopians and Sub-Saharan Africans.3
Finally, another recent study of self-reported race and genetic admixture in Cleveland, Ohio, showed that while 93 percent of those who self-identified as “White” had predominantly European genetic backgrounds, only 4 percent of those self-identified as “Black” had predominantly African genetic backgrounds4. These results illustrate the problem with “racial profiling” in medicine. For example, a physician could not use “self-described” race to prescribe drugs for African-American patients in Cleveland because any particular African-American individual might have European genes controlling the metabolic pathways the race-specific drug was supposed to impact. Similarly, doctors prescribing European race-specific drugs to Greeks might be better off prescribing them African drugs.
This is the real meaning of the idea of “personalized” medicine; specific genotypes interacting with particular environments determine customized treatment. Thus a person with a particular set of physical characteristics will not necessarily adhere to a particular medical profile. The early results with BiDil did not indicate ineffectiveness on persons of European descent, rather the results showed greater statistical significance in self-described African-Americans. Dr. Jay Cohn, the originator of BiDil, stated that he prescribes the drug to “White” patients who don’t respond well to other drugs5. This is hardly a case for racial medicine. The data on medically important genetic variation uncovered thus far do not support racial medicine6.
