The first assessment of Angiotensin-Converting Enzyme 1 (ACE1) D/I polymorphism and demographic factors in association with COVID-19 outcomes in the Moroccan Population

Background: SARS-CoV-2 responsible for the COVID-19 pandemic, infiltrates the human body by binding to the ACE2 receptor in the respiratory system cell membranes, leading to severe lung tissue damage. An analog of ACE2, ACE1, has gained attention due to its well-known Deletion/Insertion (D/I) polymorphism, which seems to be associated with COVID-19 outcomes. This study aims to reveal the allelic and genotypic frequencies of the rs4646994 polymorphism in the Moroccan population and investigate the association between COVID-19 outcomes and both genotypic and demographic data.

Methods and results: We screened 162 Moroccan COVID-19 patients for the ACE1 gene D/I polymorphism using PCR amplification of the ACE1 polymorphic region within intron 16. Statistical analysis of the relationship between COVID-19 outcomes and each of the genetic and demographic data was performed using R software. The D allele was present in 74% of subjects. Homozygous (II) and heterozygous (DI) genotypes for the Insertion allele were present in 41.4% and 5.6% of patients, respectively. The median age in the COVID-19 'critical symptoms' category was significantly higher and gradually decreased with less severe symptoms. Similarly, males were significantly overrepresented in the 'critical symptoms' category, while females predominated in the 'mild symptoms' category.

Conclusions: The present study reports the prevalence of ACE1 D/I alleles for the first time in the Moroccan population and confirms the strong association of severe COVID-19 outcomes with male sex and older age. Moreover, this work is the first to explore the relationship between ACE1 D/I polymorphism and COVID-19 clinical outcomes in North African adults. The lack of a significant association may be due to cohort size or population-specific factors. A comprehensive investigation in a larger North African cohort is highly recommended.