Association of Renin-Angiotensin Pathway Gene Polymorphisms with COVID-19 Susceptibility and Severity in Moroccans: A Case-Control Study.

Infection by the recent SARS-CoV-2 virus causes the COVID-19 disease with variable clinical manifestations ranging from asymptomatic or mild respiratory symptoms to severe respiratory distress and multiorgan failure. The renin-angiotensin system, responsible for maintaining homeostasis and governing several critical processes, has been considered the main system involved in the pathogenesis and progression of COVID-19. Here, we aimed to assess the possible association between variants in the RAS-related genes and COVID-19 susceptibility and severity in a sample of the Moroccan population. A total of 325 individuals were recruited in this study, with 102 outpatients, 105 hospitalized patients, and 118 healthy controls negative for SARS-CoV-2 infection, and subjected to NGS gene panel sequencing containing eleven RAS pathway genes. A total of 65 functional variants were identified, including 63 missenses, 1 splice, and 1 INDEL. Most of them were rare, with 47 (72%) found in a single individual. According to the common disease/common variant hypothesis, five common candidate variants with MAF > 10% were identified (ACE2 rs2285666, TMPRSS2 rs12329760, AGT rs699 genes, ACE rs4341, and ACE rs4343). Statistical analysis showed that the ACE rs4343 AA genotype was associated with a 2.5-fold increased risk of severe COVID-19 (p = 0.026), and the T genotype of the ACE2 rs2285666 variant showed a borderline association with susceptibility to SARS-CoV-2 in males (p = 0.097). In conclusion, our results showed that the RAS pathway genes are highly conserved among Moroccans, and most of the identified variants are rare. Among the common variants, the ACE rs4343 polymorphism would lead to a genetic predisposition for severe COVID-19.