Polymorphisms of ACE (I/D) and ACE2 receptor gene (Rs2106809, Rs2285666) are not related to the clinical course of COVID‐19: A case study

Karakaş Çelik, Sevim; Çakmak Genç, Güneş; Pişkin, Nihal; Açikgöz, Bilgehan; Altinsoy, Bülent; Kurucu İşsiz, Başak; Dursun, Ahmet

Coronavirus disease 2019 (COVID‐19) is an infectious disease, and the reason behind the currently ongoing pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Angiotensin‐converting enzyme (ACE2) has been recognized as the specific receptor of the SARS‐CoV‐2 virus. Although the possible effect of ACE2 gene polymorphism remains unknown, human ACE2 receptor expression influences SARS‐CoV‐2 susceptibility and COVID‐19 disease outcome. In this study, we aimed to investigate the relationship between ACE gene I/D polymorphism, ACE2 receptor gene polymorphism, and COVID‐19 severity. ACE gene insertion/deletion (I/D) polymorphism and ACE2 receptor gene rs2106809 and rs2285666 polymorphisms were determined using polymerase chain reaction (PCR) and PCR‐based restriction fragment length polymorphism methods, respectively, in 155 COVID‐19 patients who were divided into three groups (mild, moderate, and severe) according to clinical symptoms. However, the distribution of genotype and allele frequencies of ACE gene I/D, ACE2 receptor gene rs2106809, and rs2285666 polymorphisms were not statistically significant in all groups. In conclusion, in the study population, ACE gene I/D, ACE2 receptor gene rs2106809, and rs2285666 polymorphisms were not associated with the severity of COVID‐19 infection. Although ACE2 receptor gene expression may affect the susceptibility to COVID‐19, there is no existing evidence that the ACE or ACE2 gene polymorphisms are directly associated with COVID‐19 severity. Interindividual differences in COVID‐19 severity might be related to epigenetic mechanisms of ACE2 receptor gene expression or variations in other genes suggested to play a critical role in COVID‐19 pathogenesis such as pro‐inflammatory cytokines and coagulation indicators.