More than 275 million completely new genetic variants have been discovered in humans – and some of them could indicate an increased risk of cancer or diabetes.
Researchers led by the National Institutes of Health (NIH) in Bethesda, Maryland, revealed the findings after examining the genomes of 245,000 Americans, about half of whom were minorities.
Most variants had no impact on health, the researchers said, but nearly 4 million were found in genes linked to a higher risk of cancer, diabetes and heart disease, among other diseases.
Some of the variants were discovered on genes linked to cancer and diabetes (stock image)
Dr. Josh Denny, the study's lead author, said: “Sequencing diverse populations can lead to new drug targets that are relevant to everyone.”
“It can also help uncover inequalities that lead to specific treatments for people suffering from higher disease burdens or other illnesses.”
He added: “This is huge.”
The research is part of the All of Us program, the $3.1 billion national project aimed at closing the gap in genetic research that has so far focused primarily on people of white backgrounds.
It is estimated that almost 90 percent of genetic studies to date have been conducted on people of European descent.
The project aims to change that by assessing the health profiles — including genetics — of one million U.S. adults, about half from minorities, by the end of 2026.
Dr. Alicia Martin, a population geneticist at Massachusetts General Hospital in Boston, said the project is a “huge resource, particularly for African American, Hispanic and Latino genomes.”
“This is massively missing from the vast majority of large biobank resources and genomics consortia,” she added to Nature.
The latest findings were published today in a package published by Nature, Communications Biology and Nature Medicine.
In one of the papers, in which nearly 40 percent of the participants were minorities, researchers found 611 genetic markers that could drive the progression of diabetes – 145 of which were previously unknown.
They said the new variants could help inform diabetes care, particularly for adults from minority backgrounds.
In another study, researchers looked at pathogenic variants – or genetic variants that increase the risk of a particular disease, such as cancer.
They found that 2.3 percent of people of European descent had a pathogenic variant.
For comparison: For people of African descent, this value fell to 1.6 percent.
“It's obviously a huge gap because most of the world's population is not of European descent,” said Dr. Denny.
Current studies have already shown how genetic diversity can affect disease risk.
Variants in the APOL1 gene discovered in 2010 are responsible for 70 percent of the increased risk of chronic kidney disease and dialysis seen in people in the United States of sub-Saharan African ancestry.
Likewise, sequencing the genetic code of 5,000 people of African descent in Dallas discovered a class of drugs called PCSK9 inhibitors that dramatically reduce very high levels of low-density lipoprotein (LDL) – the so-called bad cholesterol.
Much more work is needed to understand how the new genetic variants contribute to different health conditions, but scientists believe they could be used to refine tools for calculating a person's risk of disease.