DBMI Research Sheds Light on the Roles of Genetics and Home Environment to COVID-19 Susceptibility

Investigators in both the Columbia University Department of Biomedical Informatics and the Department of Computational Biomedicine at Cedars-Sinai led a recent study to find out which factors influenced susceptibility to COVID-19 infection and disease severity the most. Was it genetics? Or was it home environment, meaning the germs circulating throughout your everyday life?

The findings, published in the peer-reviewed journal Nature Communications, suggest that more was in play than either factor alone.

“Our results suggest that initially, differences in shared home environment influenced who was infected with COVID-19 more than genetic differences,” said Kathleen Brown, MA, first author of the study and a DBMI PhD candidate. “Over time, however, the importance of these differences in shared home environment decreased—and the importance of genetics increased—eventually eclipsing shared home environment.”

DBMI PhD student Kathleen Brown

COVID-19 has infected more than 340 million people in the U.S., underscoring the urgency in conducting therapeutic research and uncovering potential treatments. However, until this study, little was known about how an individual’s environment and genetic background impacted their experience with the virus.

Using electronic health records from New York-Presbyterian/Columbia University Irving Medical Center, investigators identified 12,764 patients who received conclusive results—either positive or negative—from a PCR test for COVID-19. These patients belonged to 5,676 families with an average of 2.5 family members who had a bout of COVID-19. The time frame studied was Feb. 21, 2020, to Oct. 24, 2021.

The investigators’ analysis found that at the start of the pandemic, genetics accounted for 33% of variation in susceptibility. By the second half of the research study, however, genetics accounted for 70% of variation in susceptibility.

When measuring patients’ severity of COVID-19, investigators also found that a patient’s genetics were more of a factor than their home environment. Disease severity was defined by length of hospital stay. Genetics explained 41% of variation while shared environment explained 33%.  

“We were especially surprised by the percentages of susceptibility,” said Nicholas Tatonetti, PhD, senior and corresponding author of the study, vice chair of Operations in the Department of Computational Biomedicine and DBMI Adjunct Associate Professor. “Since this is an infectious disease, we assumed that home environment differences would explain most variation for the entirety of the study.”

While Tatonetti says his team of investigators cannot know for certain, they suspect that over time, discrepancies between people’s home environments changed in important ways.

“This work also suggests that the specific genetic factors influencing susceptibility and severity have not been fully identified,” said Tatonetti. “This is very important in terms of directing resources and defining future research goals.”

Related Information

The study, titled Estimating the heritability of SARS-CoV-2 susceptibility and COVID-19 severity, was published Jan. 8, 2024, in Nature Communications. Kathleen Brown is the lead author. Nicholas Tatonetti is the senior and corresponding author.

Undina Gisladottir and Michael Zietz, both PhD students in the Columbia Department of Biomedical Informatics, and Vijendra Ramlall, a PhD graduate in the Columbia Department of Systems Biology, were co-authors on this study.

This study was supported by the National Institutes of Health National Institute of General Medical Sciences R35GM131905.

This media release was originally developed by Cara Martinez, Manager, Science Communications, at Cedars-Sinai.