Editor’s note: This is a guest post by Whitney Stewart and Hans C. Andersson MD, co-authors of Genomics: A Revolution in Healthcare and Disease Discovery. To listen to Whitney and Dr. Andersson discuss Genomics and the importance of genetics and genomics to our modern lives, listen to their episode on The Lerner Podcast.
By Whitney Stewart and Hans C. Andersson MD, co-authors of Genomics: A Revolution in Healthcare and Disease Discovery
Eight months after news outlets first reported cases of an unknown illness with pneumonia-type symptoms, now known as Covid-19, lab scientists and frontline doctors are still trying to clarify who is at increased risk for this illness, who suffers a more severe case, and why? Does blood type, race, or genetics affect the risk of infection and illness outcome? Do racial disparities in healthcare play a role in Covid-19 risk and recovery? Finding answers to these questions is crucial to patient care during this pandemic and to the future wellbeing of the world.
The Centers for Disease Control and Prevention (CDC) recently updated their list of medical conditions that increase risk for severe illness from Covid-19. These include cancer, chronic kidney disease, COPD, weakened immune system from organ transplant, obesity, heart conditions, Type 2 diabetes, and a genetic disorder called sickle cell disease. Other serious conditions that involve the respiratory, endocrine, circulatory, or immune system—including inherited diseases like cystic fibrosis, thalassemia, and primary immune deficiency—might also increase risk for severe illness.
The CDC also reports that people of racial and ethnic minorities infected with Covid-19 are hospitalized at a higher rate than non-Hispanic white people. Non-Hispanic American Indian or Alaska Native persons are hospitalized 5.3 times more often than non-Hispanic White persons. Non-Hispanic Black persons and Hispanic or Latino persons are hospitalized 4.7 times more often than non-Hispanic White persons. This healthcare disparity demands attention.
Whereas some Covid-19 researchers focus on co-morbidities and disease risk, others are looking at genomics. Dr. Priya Duggal, epidemiologist at the Johns Hopkins Bloomberg School of Public Health, is studying young people with no underlying medical conditions who become infected with Covid-19. Some of these young people are hospitalized and others are not. Dr. Duggal is attempting to identify genes that might make someone more likely to develop severe illness. “We don’t have clinical answers for [these] things, and we’re hoping genetics offers answers to some of these questions,” Duggal says.
Although scientists throughout the world are in the early stages of Covid-19 genomic research, a few have already made preliminary discoveries. According to a study published in the Journal of Virology, for example, genetic variability of the human leukocyte antigen (HLA) gene family may affect susceptibility to Covid-19 and severity of the disease. Also, genetic research reported in Science shows that the interaction between the viral spike protein of SARS-CoV-2 and the human gene ACE2 is important to infection. The authors write, “The spike protein S of SARS coronavirus 2 (SARS-CoV-2) binds ACE2 on host cells to initiate entry, and soluble ACE2 is a therapeutic candidate that neutralizes infection by acting as a decoy.”
Another genetic finding involves the APOE gene, often associated with Alzheimer’s Disease. According to a study in the Journal of Gerontology, having two copies of the APOE e4 gene increases the risk of severe Covid-19 infection, independent of preexisting dementia, cardiovascular disease, and type-2 diabetes.
Andrea Ganna, a biostatistician at the University of Helsinki, is organizing the COVID-19 Host Genetics Initiative, to study the genetic bases of COVID-19 susceptibility and severity. Its mission is to bring together “the human genetics community to generate, share and analyze data to learn the genetic determinants of COVID-19 susceptibility, severity and outcomes.” Penn Medicine Biobank, which has 60,000 participants; FinnGen, which has collected DNA from 5 percent of Finland’s entire population; and the UK Biobank, with samples from 500,000 participants, are among the databanks that have agreed to share DNA data.
Personal genomics companies like Ancestry and 23andMe are asking customers if they would like to be part of research. Customers who have already given DNA samples, and who consent to take part in research, answer questions about their social distancing measures, symptoms, and COVID-19 test results.
According to Ancestry’s July 6, 2020 news release, their scientists “identified a DNA region that appears to be associated with COVID-19 susceptibility near the IVNS1ABP gene. This DNA region appears to be associated with an increased rate of COVID-19 infection in males but not females…The human IVNS1ABP gene creates a protein that is used in influenza virus replication.” Ancestry says it is preparing a detailed report of its findings and invites other scientists to review their work and determine if it holds up to rigorous scientific scrutiny.
Preliminary results of a study of Covid-19 from 23&Me, released June 8, 2020, reveals that O blood type appears to be protective against the virus when compared to other blood types. Another study from Harvard Medical School, published in the Annals of Hematology, show results on blood type. Researchers there found that “symptomatic individuals with blood types B and AB who were Rh positive were more likely to test positive for COVID-19, while those with blood type O were less likely to test positive.”
Scientists are still in the early stages of Covid-19 genomic research that could lead to a better understanding of individual susceptibility to Covid-19. Future molecular insights may help scientists realize the hope of using genomics and personalized medicine to prevent infection with SARS-CoV-2 and offer novel therapies for COVID-19. While the world waits for these insights, interested readers can strengthen their understanding of human genomics, and perhaps take part in clinical studies.
Additional Resources: Discussion Guide for Genomics