Study on the correlation between single nucleotide polymorphism frequency in TYK2 gene with COVID-19 disease

The diversity in outcomes of COVID-19 infection and understanding its underlying reasons have led toa global health challenge. Genetic features, especially variations in immune system genes, are considered as crucial factors contributing to the clinical diversity resulting from infections with viruses such as SARS-CoV-2. In this study, DNA was extracted from blood samples of 220 COVID-19 patients. The PCR-RFLPmethod was employed to identify single nucleotide polymorphisms in the Tyrosine Kinase 2 (TYK2) gene. After PCR amplification, the PCR products were enzymatically digested with AluI enzyme, and the resulting fragments were separated using gel electrophoresis. Phenotypes of each patient were determined by analyzing the created fragments, and for final confirmation, some samples were sent for sequencing. The study population included 102 recovered patients with mild COVID-19 and 118 deceased patients with severe disease. The frequency of the rs11085727 polymorphism in the TYK2 gene was statistically examined in both patient groups, revealing a significantly higher frequency in the deceased group compared to the recovered group (p< 0.05). Examining genetic factors and their variations, especially investigating single nucleotide polymorphisms in genes related to the innate immune system, can play a significant role in predicting susceptibility to COVID-19 and adopting personalized therapeutic approaches based on patients' genetics. According to the results obtained in this research, the rs11085727 polymorphism in the TYK2 gene is likely associated with the severity of COVID-19.