Nasal gene expression of angiotensin-converting enzyme 2 in children and adults

Differential expression of angiotensin-converting enzyme 2 (ACE2), the receptor through which coronavirus enters a host, is the suspected reason why children are less likely to be infected with COVID-19. To test this theory, researchers in New York compared ACE2 gene expression in the nasal epithelium of patients aged 4–60 years old.

Differential expression of angiotensin-converting enzyme 2 (ACE2), the receptor through which coronavirus enters a host, is the suspected reason why children are less likely to be infected with COVID-19. To test this theory, researchers in New York compared ACE2 gene expression in the nasal epithelium of patients aged 4–60 years old. The retrospective study included 305 people within the Mount Sinai Health System who provided samples during 2015–18 for a separate project. Analysis revealed that ACE2 gene expression was lowest—2.40 mean log2 counts per million—among children aged 10 years or younger but increased markedly among older children and young adults. By age 25 years and older, the mean log2 counts per million was up to 3.09. Although the study failed to include populations older than age 60 years, the findings suggest that lower ACE2 expression in children relative to adults may explain the lower prevalence of COVID-19 in children.