No evidence for allelic association between Covid-19 and ACE2 genetic variants by direct exome sequencing in 99 SARS-CoV-2 positive patients

Abstract

BackgroundCoronaviruses (CoV) are a large family of viruses that are common in people and many animal species. Animal coronaviruses rarely infect humans with the exceptions of the Middle East Respiratory Syndrome (MERS-CoV), the Severe acute respiratory syndrome coronavirus (SARS-CoV), and now SARS-CoV-2, which is the cause of the ongoing pandemic of coronavirus disease 2019 (COVID-19). Many studies suggested that genetic variants in ACE2 gene may influence the host susceptibility/resistance to SARS-CoV-2 virus according to the functional role of ACE2 in human pathophysiology. However, all these studies have been conducted in silico based on epidemiological and population data. We therefore investigated the occurrence of ACE2 variants in a cohort of 99 Italian unrelated individuals clinically diagnosed with coronavirus disease 19 (COVID-19) to experimental demonstrate allelic association with disease severity. MethodsBy whole-exome sequencing we analysed 99 DNA samples of severely and extremely severely COVID-19 patients hospitalized at the University Hospital of Rome "Tor Vergata" and Bambino Gesu Hospital in Rome. ResultsWe identified three different germline variants, one intronic (c.439+4G>A) and two missense (c.2158A>G, p.Asn720Asp; c.1888G>C, p.Asp630His), in 26 patients with a similar frequency between male and female and a not statistically different frequency, except for c.1888G>C, (p.Asp630His) with the ethnically matched populations (EUR). ConclusionsOur results suggest that there is not any ACE2 exonic allelic association with disease severity. It is possible that rare susceptibility alleles are located in the non-coding region of the gene able to control ACE2 gene activity. It is therefore of interest, to explore the existence of ACE2 susceptibility alleles to SARS-Co-V2 in these regulatory regions. In addition, we found no significant evidence that ACE2 alleles is associated with disease severity/sex bias in the Italian population.