A Systematic Review on Papers That Study on SNPs That Affect SARS-CoV-2 Infection & COVID-19 Severity

Background:COVID-19, caused by SARS-CoV-2 has become the most threatening issue to all populations around the world. It is directly and indirectly affecting all of us and thus, is a emergence topic dealt in global health. In order to avoid the infection, various studies have been done and still ongoing. Now having over 141 million cases of COVID19 and causing over 3 million deaths around the world, the tendency of infection and degree severity of the disease shown in different groups of people came up as an issue. Here, we reviewed 21 papers on SNPs related to SARS-CoV-2 infection severity and analyzed the results of them.Methods:The PubMed databases were searched for papers discussing SNPs associated with SARS-CoV-2 infection severity. Clinical studies with human patients and statistically showing relevance of the SNP with virus infection were included. Quality Assessment of all papers were done with Newcastle Ottawa Scale.Results:In the analysis, 21 full-text literatures out of 2956 screened titles and abstracts, including 63496 cases, were included. All were human based clinical studies, some based on certain regions gathered patient data and some based on big databases obtained online. ACE2, TMPRSS2, IFITM3 are the genes mentioned most frequently that are related with SARS-CoV-2 infection. 20 out of 21 studies mentioned one of more of those genes. The relevant genes according to SNPs were also analyzed. rs12252-C, rs143936283, rs2285666, rs41303171, and rs35803318 are the SNPs that were mentioned at least twice in two different studies.Conclusions: We found that ACE2, TMPRSS2, IFITM3 are the major genes that are involved in SARS-CoV-2 infection. The mentioned SNPs were all related to one or more of the above mentioned genes. There were discussions on certain SNPs that increased the infection severity to certain ethinic groups more than the others. However, as there is limited follow up and data due to shortage of time history of the disease, studies may be limited.