Evaluation of the relationship between different variants of Alpha 1 antitrypsin and the severity of COVID-19 disease

Background: and Aim In late 2019, incidence of respiratory diseases increased due to the outbreak of Corona virus. A1AT is a serine protease which its deficiency causes lung disease. In this study, it was hypothesized that different variants of SERPINA1 gene affect the severity of COVID-19 disease. Materials: and methods: 42 Swab samples containing purified DNA along with RNA virus, patients with COVID-19 from the age of 25-60 years were classified into three study groups contain of 14 patients each; outpatients, inpatients and the patients that admitted in intensive care units. The PCR method were used to amplification, of SERPINA1 gene, then the PCR product were sequenced by Sanger sequencing and the results were analyzed. Results: : The result of this study depicted that in the 3 outpatient, inpatient, and ICU study groups, the non-synonymous SNP, polymorphism in locus 5895 C> G (exon 2) with a frequency of 33.3% in which the amino acid alanine was changed to glycine was observed in the ICU group ,while in outpatient, inpatient groups two non-synonymous polymorphisms in locus 5646 and 5892 (exon 2) were reported , due to the high frequency of polymorphisms at position 5895 in the ICU group compared to other study groups may be related to the severity of symptoms of COVID-19 disease with this polymorphism Also, among the synonymous polymorphisms of SNP, in locus 11295 (exon 5) with a frequency of 21.4% in the outpatient group, probably showed the highest resistance against COVID-19.