ABSTRACT
Background: Coronaviruses (CoV) are a large family of viruses that are common in humans 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). Several studies suggested that genetic variants in the ACE2 gene may influence the host susceptibility or resistance to SARS-CoV-2 infection according to the functional role of ACE2 in human pathophysiology. However, many of 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 131 Italian unrelated individuals clinically diagnosed with COVID-19 and in an Italian control population, to evaluate a possible allelic association with COVID-19, by direct DNA analysis.Methods: As a pilot study, we analyzed, by whole-exome sequencing, genetic variants of ACE2 gene in 131 DNA samples of COVID-19 patients hospitalized at Tor Vergata University Hospital and at Bambino Gesù Children’s Hospital, Rome. We used a large control group consisting of 1,000 individuals (500 males and 500 females).Results: We identified three different germline variants: one intronic c.439+4G>A and two missense c.1888G>C p.(Asp630His) and c.2158A>G p.(Asn720Asp) in a total of 131 patients with a similar frequency in male and female. Thus far, only the c.1888G>C p.(Asp630His) variant shows a statistically different frequency compared to the ethnically matched populations. Therefore, further studies are needed in larger cohorts, since it was found only in one heterozygous COVID-19 patient.Conclusions: Our results suggest that there is no strong evidence, in our cohort, of consistent association of ACE2 variants with COVID-19 severity. We might speculate that rare susceptibility/resistant alleles could be located in the non-coding regions of the ACE2 gene, known to play a role in regulation of the gene activity.
Subject(s)
COVID-19ABSTRACT
Background: Coronaviruses (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. Methods: By 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. Results: We 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). Conclusions: Our 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.
Subject(s)
Coronavirus Infections , Infections , COVID-19 , Nijmegen Breakage SyndromeABSTRACT
The Angiotensin-converting enzyme 2 (ACE2) has been recently recognized as the entry receptor of the novel pathogenic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-Cov-2). The presence of structural and sequence variants in ACE2 gene may affect its expression in different tissues and determine a differential response to SARS-Cov-2 infection and COVID19-related phenotype. The present study investigated the genetic variability of ACE2 in terms of Single Nucleotide Variants (SNVs), Copy Number Variations (CNVs) and expression Quantitative Loci (eQTLs) in a cohort of 268 individuals representative of the Italian general population. The analysis identified 5 SNVs (rs35803318, rs41303171, rs774469453, rs773676270, rs2285666) which displayed a significantly different frequency distribution in the Italian cohort compared to the worldwide populations. The analysis of eQTLs located in and targeting ACE2, revealed a high distribution of eQTL variants in different brain tissues, suggesting a possible link between the genetic variability of ACE2 and the neurological complications in patients with COVID19. Further research is needed to clarify the possible relationship between ACE2 expression and the susceptibility to neurological complications in patients with COVID19. In fact, patients at higher risk of neurological involvement may need different monitoring and treatment strategies in order to prevent severe, permanent brain injury.