The coronavirus disease 2019 (COVID-19) is a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. COVID-19 has a variety of clinical manifestations, ranging from asymptomatic infection or mild symptoms to severe symptoms. Severe COVID-19 patients experience cytokine storm, resulting in multi-organ failure and even death. Male gender, old age, and pre-existing comorbidities (such as hypertension and diabetes ) are risk factors for COVID-19 severity. Recently, a series of studies suggested that genetic defects might also be related to disease severity and the cytokine storm occurence. Genetic variants in key viral immune genes, such as TLR7 and UNC13D, have been identified in severe COVID-19 patients from previous reports. In this review, we summarize the mechanisms underlying immune responses against SARS-CoV-2 and genetic variants that associated with the severity of COVID-19. The study of genetic basis of COVID-19 will be of great benefit for early disease detection and intervention.
Keywords: germline variants; immunodeficiency; severe COVID-19 patients.