Charles Rotimi first realized the future was passing him by around 2005. The Human Genome Project had recently finished spelling out an entire set of human DNA. Following that breakthrough, scientists in six countries across the globe had begun collecting blood samples to find genes responsible for various conditions, including serious diseases, which could lead to treatments. And Rotimi, who was leading that collection effort in Africa, had the sick feeling that history was repeating itself.
He wasn’t concerned about himself so much as his homeland. In the past, African patients have had poor access to medical advances, even as scientists use them as research subjects. Rotimi worried that genetics might again exploit the 1 billion people n sub-Saharan Africa, ignoring their need for treatments for HIV, tuberculosis, malaria and cancer. “The genomic revolution was going to fly over Africa,” he says, “and tomorrow’s medicine will not work for all.”
His concern was well founded. Over the next few years, scientists came out with a frenzy of discoveries about our DNA that could possibly lead to new treatments for diabetes, cancer, psychiatric illnesses and other serious diseases. But they were drawing from a small slice of the world: Nearly all of the published work was based on populations with European ancestry. By 2009, fewer than 1 percent of the several hundred genome investigations included Africans.
The genomics revolution soon began to sputter. Being able to know the exact genetic makeup of each patient was to bring a new era of treatments tailored for each individual. But doing so depends on finding minute variations in our DNA that correlate with the occurrence of disease or bad drug reactions. This task requires the full range of genetic variation among as many humans as possible. Otherwise, genomics research is like a search party that circles the same few trees looking for signs of the killer rather than spreading out through the entire woods.
The richness of African genomes is a product of the evolution of our species. Modern Homo sapiens originated in Africa about 200,000 years ago. About 100,000 years later, 1,600 or so men and women—from a population of at least 20,000 and likely much more—left the continent and spread around the globe, eventually reaching Europe and, more recently, the Americas. “In other words,” wrote University of Washington geneticist Mary-Claire King and colleagues in a 2017 commentary, “about 99 percent of our evolutionary experience as a species was spent in Africa.”
Whatever genetic diversity existed across the continent until then was almost entirely left behind when that small group emigrated—and it is there still, hidden in the genes of each African. That is partly why Rotimi was so dismayed by the exclusion of Africa from genomics. “We are all Africans beneath our skin,” he says.
More and more scientists are coming around to Rotimi’s view—that Africa contains one of the greatest weapons in the quest to combat cancer: the DNA of its people.
Unpacking the Genome
As a Nigerian-born scientist specializing in genetics and health disparities, Rotimi foresaw the consequences of omitting Africans from genome studies years before many other researchers even noticed. And he was uniquely positioned to do something about it.
Born in Benin, Nigeria’s fourth-largest city, Rotimi first saw health inequalities in a big way in America. He came to the U.S. for graduate school at the University of Mississippi, where many of the state’s wealthiest families send their children, a trip that introduced him to his first Big Mac. “I just couldn’t eat it,” he recalls. “I couldn’t fathom the concept of bread, meat and leaves together.”
Worse was the taste of inequality he got while traveling around the state. “That is when poverty speaks very loud, when you are in an environment with a lot of resources, but you don’t seem to have them,” he says.
He returned to Nigeria armed with a graduate degree. But after six months of job searching, he had yet to find an opportunity to do the research he knew was needed. He returned to the U.S., eventually earning doctorate degrees in public health and epidemiology.
Those years deepened his awareness of the importance of genes to health. Life in Nigeria had already shown him that sickle cell disease was fated by birth, not by upbringing. Now, his research on hypertension among Africans around the world showed him that although lifestyle and the environment shape health, so does DNA. -NewsWeek