DNA databases are too white, so genetics doesn’t help everyone. How do we fix that?

Tina Hesman Saey at ScienceNews: “It’s been two decades since the Human Genome Project first unveiled a rough draft of our genetic instruction book. The promise of that medical moon shot was that doctors would soon be able to look at an individual’s DNA and prescribe the right medicines for that person’s illness or even prevent certain diseases.

That promise, known as precision medicine, has yet to be fulfilled in any widespread way. True, researchers are getting clues about some genetic variants linked to certain conditions and some that affect how drugs work in the body. But many of those advances have benefited just one group: people whose ancestral roots stem from Europe. In other words, white people.

Instead of a truly human genome that represents everyone, “what we have is essentially a European genome,” says Constance Hilliard, an evolutionary historian at the University of North Texas in Denton. “That data doesn’t work for anybody apart from people of European ancestry.”

She’s talking about more than the Human Genome Project’s reference genome. That database is just one of many that researchers are using to develop precision medicine strategies. Often those genetic databases draw on data mainly from white participants. But race isn’t the issue. The problem is that collectively, those data add up to a catalog of genetic variants that don’t represent the full range of human genetic diversity.

When people of African, Asian, Native American or Pacific Island ancestry get a DNA test to determine if they inherited a variant that may cause cancer or if a particular drug will work for them, they’re often left with more questions than answers. The results often reveal “variants of uncertain significance,” leaving doctors with too little useful information. This happens less often for people of European descent. That disparity could change if genetics included a more diverse group of participants, researchers agree (SN: 9/17/16, p. 8).

One solution is to make customized reference genomes for populations whose members die from cancer or heart disease at higher rates than other groups, for example, or who face other worse health outcomes, Hilliard suggests….(More)”.