Oladejo Babayemi Olawale, Adeboboye Covenant Femi, Adebolu Tinuola Tokunbo
Department of Microbiology, Federal University of Technology, P.M.B. 704, Akure, Nigeria.
Egypt J Med Hum Genet. 2020;21(1):77. doi: 10.1186/s43042-020-00122-z. Epub 2020 Dec 31.
Numerous research studies have identified specific human gene variants that affect enhanced susceptibility to viral infections. More recently is the current pandemic where the SARS-CoV-2 infection has shown a high degree of person-to-person clinical variability. A wide range of disease severity occurs in the patients' experiences, from asymptomatic cases, mild infections to serious life threatening conditions requiring admission into the intensive care unit (ICU).
Although, it is generally reported that age and co-morbidities contribute significantly to the variations in the clinical outcome of the scourge of COVID-19, a hypothetical question of the possibility of genetic involvement in the susceptibility and severity of the disease arose when some unique severe outcomes were seen among young patients with no co-morbidity. The role human genetics play in clinical response to the viral infections is scarcely understood; however, several ongoing researches all around the world are currently focusing on possible genetic factors. This review reports the possible genetic factors that have been widely studied in defining the severity of viral infections using SARS-CoV-2 as a case study. These involve the possible involvements of ACE2, HLA, and TLR genes such as TLR7 and TLR3 in the presentation of a more severe condition.
Understanding these variations could help to inform efforts to identify people at increased risk of infection outbreaks through genetic diagnosis of infections by locating disease genes or mutations that predispose patients to severe infection. This will also suggest specific targets for therapy and prophylaxis.
众多研究已确定了影响人类对病毒感染易感性增强的特定基因变异。最近的新冠疫情中,严重急性呼吸综合征冠状病毒2(SARS-CoV-2)感染呈现出高度的人际临床变异性。患者经历了广泛的疾病严重程度,从无症状病例、轻度感染到需要入住重症监护病房(ICU)的严重危及生命的情况。
尽管普遍报道年龄和合并症对新冠疫情临床结果的差异有显著影响,但当在无合并症的年轻患者中观察到一些独特的严重结果时,就出现了一个关于基因是否参与该疾病易感性和严重程度的假设性问题。人类遗传学在对病毒感染的临床反应中所起的作用几乎不为人知;然而,目前世界各地的几项正在进行的研究都聚焦于可能的遗传因素。本综述以SARS-CoV-2为例,报告了在确定病毒感染严重程度方面已被广泛研究的可能遗传因素。这些因素包括血管紧张素转换酶2(ACE2)、人类白细胞抗原(HLA)以及Toll样受体(TLR)基因如TLR7和TLR3在病情更严重时的可能作用。
了解这些变异有助于通过对感染进行基因诊断来确定感染爆发风险增加的人群,即定位使患者易患严重感染的疾病基因或突变。这也将为治疗和预防提出具体靶点。