Genetic variability in the expression of the SARS-CoV-2 host cell entry factors across populations.

The entry of SARS-CoV-2 into host cells is dependent upon angiotensin-converting enzyme 2 (ACE2), which serves as a functional attachment receptor for the viral spike glycoprotein, and the serine protease TMPRSS2 which allows fusion of the viral and host cell membranes. We devised a quantitative measure to estimate genetic determinants of ACE2 and TMPRSS2 expression and applied this measure to >2500 individuals. Our data show significant variability in genetic determinants of ACE2 and TMPRSS2 expression among individuals and between populations, and indicate a genetic predisposition for lower expression levels of both key viral entry genes in African populations. These data suggest that host genetics related to viral entry mechanisms might influence interindividual variability in disease susceptibility and severity of COVID-19.