RESUMEN
Background: The most current threat to global health is the continuous spread of a respiratory disease known as COVID-19 Disease 2019 in recent years. COVID-19 was recognized in December 2019. It was quickly determined that a novel COVID-19 virus, which is structurally linked to the virus that causes the severe acute respiratory syndrome, was to cause (SARS). Objective: The aim of this study is to investigate the presence of effect between the rs179008 (A/T) SNP polymorphism in TLR7 gene and blood group on the severity of COVID-19. Methods: The study included 90 patients divided into three groups mild, moderate, severe, and experimental research work was conducted during the period of sample collection extended from November 2021 to February, PCR-RFLP technique was used to determine SNP rs179008 polymorphism in TLR7 in the blood. Results: A present study found non-significant differences between patient groups for TLR7 rs179008 (A, T) allele were (p=0.79152) for mild to moderate and severe, (p=0.84872) for mild and moderate and (p=0.58741) for mild and severe. When comparison (AA, AT, TT) genotypes in three groups found a significant difference between mild and moderate groups (p=0.036) for the AA genotype. Found (A blood group) more frequency than other groups but observes no significant difference between patients' group. Conclusion: We conclude that the (AA) genotype for TLR7 rs179008 polymorphism was a risk factor and effect on severity of COVID-19 infection, so (AA) can consider an independent risk factor for development of COVID-19.