Genetic diversity is a factor in health, Black geneticists insist

sharing at laugh at a nutrition class for seniors

The past year has seen dramatic efforts to address racism in public policy, the arts and the sciences. In medicine, there has been a rallying cry to stop referring to race as a risk factor for negative health outcomes and to acknowledge, instead, that racism imposes more toxic exposures, more poverty, and more stress on Black people, and that these social factors account for poorer health outcomes.

Over the summer, a group of non-Black researchers applied this lens, in a NEJM editorial, to algorithms used to guide medical treatment. In some cases, patients with very similar medical circumstances – say, a high-risk pregnancy or a failing kidney – may have different courses of treatment recommended based on algorithms that account for race. The editorial observes that sometimes different bodies do call for different treatments but suggests that there are too many examples where differences in outcomes along racial lines addressed in the algorithms actually reflect past bias.

A group of geneticists who first bonded through shared struggles as Black professionals in academia are pushing back against the editorial’s call to throw out all racial considerations in medical decision-making algorithms. The goal should instead be to replace race – an arbitrary and prejudicial classification of genetic ancestries – with genetics and social determinants in an evidence-based manner, they wrote in an editorial in the New England Journal of Medicine.

“You can’t just make a blanket statement, explained Akinyemi Oni-Orisan, PharmD, PhD, the piece’s lead author. “We need to look at every disparity on a case-by-case basis.”

Department of Epidemiology & Biostatistics PhD student Yusuph Mavura, MS, is the second author of the editorial.

Mavura, Oni-Orisan and the other authors agree that the effects of racism frequently account for what appear to be clinically relevant racial differences. But they also note that a racial adjustment for estimated glomerular filtration rate (eGFR), a measure to assess kidney function, was introduced through sound research to address earlier equation’s underperformance in predicting eGFR in patients of African descent. Cutting race from this decision algorithm would mean returning to lesser accuracy.

“We do not believe that ignoring race will reduce health disparities; such an approach is a form of naive ‘color blindness’ that is more likely to perpetuate and potentially exacerbate disparities,” the geneticists wrote.

Genetics and race have a fraught history. But, Mavura said in an interview, “if you cast genetics as racist, you starve the field from having people of color come to the table. Genetics done right is antiracist. It’s not hierarchical; it’s agnostic.

The best scientific way to ensure that genetic medicine doesn’t perpetuate racism? The answer, coming from scientists, is hardly a surprise: more data. Mavura and Oni-Orisan call for more genetic studies to actively recruit people of non-European ancestry. As of 2016, people with African ancestry accounted for about 3% of all genetic information gathered.

This isn’t just a question of propriety. All humans originated in Africa, and only a small proportion left. As a result, there is more genetic diversity among African populations than in other ethnic groups. That fact has two major implications: First, “genetic studies in non-African populations, including their clinical relevance, may not be generalizable to African populations,” the essay claims.

On the flip side, by increasing genetic studies of African populations, we are likely to discover genetic drivers of and defenses against disease that could benefit everyone.

The position has forced a re-evaluation of the way health disparities are taught to medical students at UCSF. A new anti-oppression curriculum is being developed with input from many stakeholders. Oni-Orisan and other geneticists have been asked to contribute an addendum on genetics. Science is a process of constant revision.