On Race, Medicine, Genetics, and Disparities

Always a lively topic, the Kaiser Family Foundation recently sponsored an installment of their excellent webcast, "Today's Topics in Health Disparities," entitled, Race and Genetics: The Future of Personalized Medicine.  The webcast featured Clyde Yancy (a physician from Baylor University Medical Center, which is not affiliated with Baylor College of Medicine, where I work), Dorothy Roberts, and Richard Levy.  You can read their bios on the webcast page, and the webcast has been archived in various formats.  A transcript of the session is also available.

The webcast was extremely interesting, and Roberts, whose work on the subject I greatly admire, made a number of compelling points.  I won't review it here in detail, but I did want to discuss one intriguing exchange between Yancy and Roberts.  Roberts expressed concern over the geneticization of disparities -- a topic we've addressed here -- and noted the possibility that undue attention on the genetics of disparities could divert attention and resources away from the social and economic determinants that are largely responsible for producing health disparities.

Yancy acknowledged this, but noted that numerous studies controlled for SES and still found statistically significant differences among ancestral groups in conditions like CHF.  I want to make two quick points in response to this.  First, such a finding does not control for social and economic effects on health, for the simple reason that gene expression is a product of a nonlinear dynamical system that involves myriad social, environmental, and economic factors.  As Jeremy Freese has noted, it is crucial to avoid the fallacy which attributes x% of disease causality to social and environmental factors, and 1-x% to genetics.  This is an extremely common, but deeply fallacious conceptualization, because gene expression is inextricably linked to social, environmental, and economic conditions.  Therefore, controlling for SES assuredly does not justify the conclusion that the remaining disparities must be the result of extra-social forces.

I cannot stress this enough, as this mistake is lamentably common (though I am not necessarily suggesting Yancy made such a mistake). 

The second point is hearsay, but one of the participants in a rich discussion on the Spirit of 1848 listserv (the major listserv dedicated to public health & social justice) noted that Troy Duster, an expert on issues of race, genetics, and medicine, once remarked in response to a similar point that the investigators had successfully managed to control for everything about being black in America.  This may seem glib, but there is an important point underlying the statement: controlling for SDOH as to disparities risks overstating the role gene expression plays in disparities.  As Roberts noted, and none of the panelists disagreed, we already have outstanding evidence that the primary causes of health disparities are social and economic conditions.  Why should we control for those to ascertain the role GxE plays? How much benefit, from a public health perspective, will we gain?

For a blistering, and to my mind, persuasive critique of the notion that genetics will play a central role in public health, check out Claudia Chaufan's recent dialogue in Social Science & Medicine.   

Comments

[dave porter]

You may be interested in this video of a talk by Richard S. Cooper M.D. on the uses and misuses of genetic research in health disparities.

http://blog.case.edu/ccrhd/2006/12/14/genetic_research_health_disparities

To paraphrase a bit, Dr. Cooper says that certainly there are biological and genetic differences between large population groups but those differences have nothing to do with the disparities that are measured on the public health scale.