Association of Angiotensin Converting Enzyme 2 (ACE2) Gene Polymorphisms with Disease Severity in Indian Covid-19 Patients: A Next-gen Sequencing Approach

ABSTRACT

The clinical picture of COVID-19 ranges from asymptomatic to mild, moderate or severe disease sometimes leading to death. Differences in the interaction between SARS-CoV-2 Spike (S) protein and angiotensin converting enzyme 2 (ACE2) protein may lead to differences in disease severity. We studied whether ACE2 polymorphisms are associated with disease severity and outcome. We recruited 114 patients between July 2020 - March 2022 confirmed positive by RTPCR for COVID-19 with different degrees of severity (21 mild, 29 moderate, 34 severe, 30 death) and 30 controls (10 non-vaccinated+ 20 vaccinated) who were RT-PCR negative inspite of high-risk contact. Next-gen sequencing was done on MiSeq (Illumina) using amplicon-based targeted sequencing approach using a custom-designed panel to sequence all the exons of ACE2 gene. SPSS ver.26 was used for analysis. The following ACE2 variants were identified on the Local Run Manager (LRM) software from Illumina (i) rs2285666 (c.439+4G>A) splice region variant, in controls (60%) and Patients (45.8%), (ii) rs4646140 (c.802+24G>A) intronic variant in 4/114 patients and 1/30 controls, (iii) rs41303171 ( c.2158A>G) missense variant in 2/114 patients, (iv) rs536749578 (c.2114+9T>C) intron variant, (v) rs763994205 (c.868A>C) missense variant and (vi) rs7595907 (c.656G>A) missense variant in 1/114 patient each only. rs2285666 was observed in equal frequency ( 60%) in vaccinated and non-vaccinated controls. rs2285666 was observed amongst different severity groups Mild (80.95%), Moderate (37.93%), Severe (44.11%), and Death (56.67%) revealing association with disease severity, probably having a protective effect. However, these results need to be confirmed on larger sample sizes.