DETROIT – It's a question that has vexed researchers from the beginning of the coronavirus outbreak: Why do some people get severely ill and die from COVID-19, while others have mild symptoms or none at all?
Now, scientists at two direct-to-consumer genealogy DNA companies hope to use the genomes they've collected from millions of people over the years to see if they can find a genetic explanation to answer that question.
Both 23andMe and Ancestry have launched COVID-19 studies, asking U.S. adult customers who've already submitted DNA samples to answer online questions about how the virus affected – or didn't affect – them.
"From the early days ... I think it was clear to all of us that some people were getting very, very sick when they were affected with coronavirus, and some people had hardly any symptoms at all," said Dr. Catherine Ball, chief scientific officer at Utah-based Ancestry. "It turns out that there are plenty of people who have no symptoms. The spectrum of human response to the same pathogen is unusual.
"And even with a bunch of comorbidities and other problems, it's still remarkably divergent in different people, even if they have the same age and have the same overall health. And so to geneticists, that looks like there's a genetic factor in whether people become infected in the first place or have serious or mild symptoms."
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An established data pool
With 16 million people who've already spit in vials and sent them to Ancestry for genetic testing to find blood relatives who might be closely or distantly related or learn how much of their DNA suggests their relatives came from Africa or Asia or were Native American or European, Ball said the company knew it had a potentially useful data pool to tap for COVID-19 research.
"We clearly want to take the opportunity to unleash that power to be able to see if there are genetic signals, and be able to help researchers and people making drugs and therapeutics and vaccines do smarter work faster," she said.
Of those 16 million DNA customers through Ancestry, so far about 500,000 people have already taken an online survey to participate in the company's coronavirus research.
At 23andMe, principal scientist Adam Auton said the California-based company's COVID-19 genome-wide association study launched in April.
About 10 million of its genotype customers are eligible for the study, he said. Of them, about 80% have consented to participate in research, and 600,000 customers have opted into the COVID-19 study.
"It is a really quite tremendous response to the study and I think shows that people really do want to try and contribute to help understand and fight this disease," said Auton.
Both Ancestry and 23andMe acknowledge that the bigger the sample size, the better their research will be.
"Never ask a scientist how much data she needs because she always needs more," Ball said. "We're really hoping to get a minimum of a million respondents because we need to have a decent number of people who have tested positive to give us a statistical signal."
So far, about 9,000 people in 23andMe's COVID-19 study reported that they tested positive for coronavirus.
"That's a pretty substantial number," Auton said. "However, it's the nature of genetic studies that we really need very large numbers of people to be able to draw connections between the genetic information and people's health information."
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Since the pandemic began, about 1.6 million people in the United States, a country of 330 million, have tested positive for COVID-19. As the virus continues to spread, and more people get coronavirus diagnoses, the companies suspect that the number of people who will go on to enroll in their studies also is likely to rise.
"We understand this is an evolving situation," Ball said. "And while we can't shelter in place forever, at some point, as we're opening up our cities and states, more people will start contracting the virus."
Anyone who may have already filled out an online COVID-19 survey on Ancestry.com or 23andMe.com, saying they had not yet had the virus, can go back and revise their answers later to reflect that they've contracted it.
To expand its research of people who've had COVID-19 even more, Auton said 23andMe is now offering to mail a free DNA test kit to any U.S adult who was hospitalized with COVID-19, but has not yet submitted a DNA sample to the company.
"We are essentially asking if people have been hospitalized with COVID-19, and they have recovered, if they would like to participate in our research. They can come to our website and we'll offer them a free kit," Auton said.
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"We're very much interested in trying to get the word out so that people to hear about this because really every data point is going to be pretty valuable."
23andMe has emailed customers in areas hardest hit so far in the pandemic to let them know about its study, Auton said.
"The best thing that we can do to make a difference for COVID is to really publish the results that we find and make them available to the research and scientific communities," he said.
23andMe has published more than 150 studies in peer-reviewed scientific journals, "the majority of which come from collaboration with the broader academic and the scientific community," Auton said, since it launched in 2006 with its direct-to-consumer DNA kit.
But the company ran afoul of the U.S. Food and Drug Administration in 2013, when the agency ordered 23andMe to halt the release of genetic health information to customers, saying the company had yet to prove its tests were "analytically or clinically validated."
After revamping, the company passed FDA muster in 2017, and got authorization to offer genetic health reports that outlined risk for 10 conditions, including late-onset Alzheimer’s disease and Parkinson’s disease.
Ancestry is new to the health genetics business. It launched AncestryHealth in 2019, with the disclaimer that its tests are physician-ordered and not diagnostic, but offer "health insights" into whether a person might be a carrier for cystic fibrosis or sickle cell anemia or whether there's a genetic variant associated with a higher risk for breast cancer or colon cancer.
Ball said Ancestry also will seek to publish its COVID-19 research findings, too.
"We will be doing our very best to publish our findings as quickly as possible, and making them as useful to clinicians and other researchers as quickly as possible," she said.
Hopes of developing a treatment
Ball urged people to consider participating in this research for the common good and stressed, right now, the focus is on safeguarding the privacy of its customers.
"The people who came to AncestryDNA were interested in finding out about their ancestors, their past and their history," she said. "This is our chance in this moment of history ... to take 5-10 minutes ... and do our best to help our community of friends or family and the people who we don't even know who will be coming along later.
"It's our chance to contribute to the benefit of everybody. And I think right now, it's an opportunity that resonates with a lot of people."
Auton said the research could lead to therapies or treatments for people sickened by COVID-19.
"Hopefully, that can make a difference," he said.
Follow reporter Kristen Jordan Shamus on Twitter @kristenshamus.
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