Mount Sinai Researchers: Why COVID-19 May Be Less Common in Children Than Adults
Findings Published in JAMA Could Lead to Potential Biomarker of Susceptibility
The virus that causes COVID-19 uses a receptor known as ACE2, found on the surface of certain cells in the human body, to enter its victims. Now, Mount Sinai researchers have found that children have lower levels of ACE2 gene expression than adults, which may explain children’s lower risk of COVID-19 infection and mortality. Gene expression is a measure of how much a gene is transcribed. These results, published in JAMA on Wednesday, May 20, may point to a potential biomarker of susceptibility to the virus, known as SARS-CoV-2.
“ACE2 expression may be linked to our susceptibility to COVID-19,” says lead author Supinda Bunyavanich, MD, MPH, Professor of Genetics and Genomic Sciences and Pediatrics, Icahn School of Medicine at Mount Sinai. “ACE2, which stands for angiotensin converting enzyme 2, is a receptor that some might be familiar with because of its role in blood pressure regulation. The coronavirus uses ACE2 to enter the human body, where it spreads. ACE2 is known to be present in our airway, kidneys, heart, and gut. In our study, we took this knowledge a step further, finding that there are low levels of ACE2 expression in the nasal passages of younger children, and this ACE2 level increases with age into adulthood. This might explain why children have been largely spared in the pandemic.”
The research focused on ACE2 due to its significance in COVID-19 infection. The nasal passages are usually the first point of contact for SARS-CoV-2 and the human body. Dr. Bunyavanich’s study is one of only a few examining the relationship between ACE2 in the airway and age.
The retrospective analysis, led by Dr. Bunyavanich, examined nasal passages epithelium from Mount Sinai Health System patients aged 4 to 60. The researchers found ACE2 gene expression in nasal epithelium was age-dependent, lowest in younger children and increasing with age into adulthood.
About the Mount Sinai Health System
The Mount Sinai Health System is New York City's largest academic medical system, encompassing eight hospitals, a leading medical school, and a vast network of ambulatory practices throughout the greater New York region. Mount Sinai is a national and international source of unrivaled education, translational research and discovery, and collaborative clinical leadership ensuring that we deliver the highest quality care—from prevention to treatment of the most serious and complex human diseases. The Health System includes more than 7,200 physicians and features a robust and continually expanding network of multispecialty services, including more than 400 ambulatory practice locations throughout the five boroughs of New York City, Westchester, and Long Island. The Mount Sinai Hospital is ranked No. 14 on U.S. News & World Report's "Honor Roll" of the Top 20 Best Hospitals in the country and the Icahn School of Medicine as one of the Top 20 Best Medical Schools in country. Mount Sinai Health System hospitals are consistently ranked regionally by specialty and our physicians in the top 1% of all physicians nationally by U.S. News & World Report.