ABSTRACT
Background/Objectives: During COVID-19 pandemic, it is essential to detect patients potentially at risk of life-threatening complications, due to possible specific genetic mutations. The aim of our work is to show a practical application of genetic testing, allowing a diagnosis of alpha 1 antitrypsin deficiency in cases with a severe clinical course during COVID-19 infection. Method(s): During hospitalization for COVID-19, we identified 5 patients (3 female, 2 males from two different families, age range 18-47 years) with a severe course of COVID-19 infection, requiring high pressure ventilation with high volume oxygen supply. Two months after discharge, those patients were reevaluated with respiratory function tests, biochemical tests, genetic counselling and genetic testing. A peripheral blood sampling for SERPINA1 genetic testing has been performed, using Sanger sequencing. Result(s): Two months after discharge, in all 5 patients respiratory function tests were consistent with a dysventilatory obstructive syndrome, in contrast with usual findings related to COVID-19 infection. Blood test still showed increase plasmatic transaminase concentration in 3 out of 5 patients, one having increased serum bilirubin as well. We performed SERPINA1 genetic testing showing homozygosity for SERPINA1 pathogenic mutations (c.193del and c.875C>T, respectively) in all 5 patients. Conclusion(s): These cases showed the importance of genetic testing for patients with unexplained severe COVID-19 infection. Genetic testing allowed the diagnosis of cases affected by alpha 1 antitrypsin deficiency, associated with dysventilatory obstructive syndrome, that may worsen the short and long term prognosis of COVID-19.