No Association between SARS-CoV-2 Infection and the Polymorphism of the Toll-like Receptor 7 (TLR7) Gene in Female Population

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a single-stranded RNA virus. Toll-like receptor 7 (TLR7) recognizes single-stranded RNA viruses. The TLR7 gene plays a critical role in the human innate and adaptive immune response to SARS-CoV-2 infections. Genetic factors probably affect SARS-CoV-2 infection susceptibility. In the current study, our aim was to search for genetic variations associated with COVID-19 patients in the TLR7 gene of a Korean population. We designed five gene-specific primers to cover the coding region of the human TLR7 gene. Using amplicon sequencing, we screened the genetic polymorphisms in the coding region of the TLR7 gene in COVID-19 patients and healthy controls. The genotype frequencies, allele frequencies, and Hardy-Weinberg equilibrium (HWE) were examined. We identified a low-frequency synonymous single nucleotide polymorphism (SNP) (rs864058) in the coding region of the TLR7 gene. There were no significant differences in the genotype or allele frequencies of the TLR7 rs864058 polymorphism between COVID-19 female patients and healthy controls (p = 1.0). In conclusion, TLR7 (rs864058) polymorphism is low frequency in Korean populations and is not associated with SARS-CoV-2 infection.