Impact of Host Genetic Players on Covid-19 Disease Severity: A Review of Current Knowledge and Future Prospect

The year 2020 has been more life-changing and eventful than ever due to the COVID-19 which has led us into this worldwide crisis. An interesting revelation has been made that the coronavirus is not entirely new to us as we are being infected by three types of seasonal coronavirus every year in winter resulting in the seasonal cold. However, SARS-CoV-2 (Severe Acute Respiratory Syndrome Corona Virus-2) has pioneered this pandemic in Wuhan, China last year, which has been named COVID-19. Since then, many nations were seen to have responded differently from one another against this virus such as European nations facing more devastation than the Middle East region in this pandemic. The reasons behind these phenomena were assumed to be the different safety measures taken by the nations but in reality, it has been known that the host genetics are responsible for the devastating effects of COVID-19. Many research findings have pointed out that ACE2, TMPRSS2, and HLA genes in the host genomes are responsible for the virus entry and subsequent immune response. Several studies conducted by different nations have found different COVID-19 variations within which three genes seem to provide clues explaining the individual population's differential disease susceptibility and severity of these viral strains. This review paper has summarized the recent research findings on ACE2, TMPRSS2, and HLA gene variations in different populations, and their effect on causing severity of COVID-19 among individuals, which would be helpful to persuade the importance of such patterns in genetic variation within the Bangladeshi population; so that personalized treatment may be formulated or repurposed drugs may be used to lower the profound impact of SARS-CoV-2.