Strengths and limitations of the study
This study has been conducted for the first time worldwide with 5 various genes related to the infectivity of SARS-CoV-2. This study, in addition to investigating the effect of variants on contracting COVID-19, the effect of found variants on the amino acid sequence of the related proteins, and the structure and function of the related proteins have been measured. This research confirms previous studies on the importance of genetic factors predisposing to COVID-19 in ACE2, TMPRSS2, TYK2, SLC6A20, and IFNAR2 genes. Some limitations of the study are that first of all this study only focused on genetic factors, so all other factors such as epigenetic factors, comorbidities, and lifestyle were not considered. Second, for some polymorphisms that did not show any association with contracting COVID-19, we cannot rule out the possibility that they could be associated with disease severity or death, perhaps larger sample sizes are needed to demonstrate this association.