Marla Broadfoot in The Scientist:
Among the many mysteries that remain about COVID-19, the disease caused by the new coronavirus, is why it hits some people harder than others. Millions of people have been infected, but many never get sick. Those who do can experience an ever-expanding array of symptoms, including loss of smell or taste, pink eye, digestive issues, fever, cough, and difficulty breathing. Although the elderly, those with pre-existing conditions such as heart disease, and men are most likely to suffer severe complications, hundreds of young and previously healthy people have died from the disease in the US alone. In recent weeks, researchers have begun asking whether genetics could influence the severity of symptoms. So far, they know “basically nothing,” Wendy Chung, a clinical geneticist and physician at Columbia University, tells The Scientist. She is one of hundreds of scientists launching studies to interrogate the human genome for answers. Chung and her team are racing to “recycle” and bank nasal swabs and other clinical samples from COVID-19 patients across the New York-Presbyterian Hospital System, currently in the epicenter of the coronavirus pandemic.
The researchers plan to extract the patients’ DNA and scan the genomes for tiny sequence variations associated with symptoms listed in their electronic health records. Prior research has uncovered gene variants that can alter a person’s chances of contracting an infectious disease. The most famous example is a mutation in the CCR5 gene, which offers protection against HIV. Other variants can affect what happens once the virus is inside the human body, leading to strikingly disparate outcomes from one person to the next, says Priya Duggal, a geneticist at Johns Hopkins University. Duggal has previously shown that variants in the human leukocyte antigen (HLA) genes, which influence the body’s immune response, may explain why some people spontaneously clear hepatitis C infection whereas others are left with chronic disease.