In contrast, AATD is characterized by a reduction in AAT serum levels or activity, and in 98% of cases, it is caused by two different variants of SERPINA1 gene [8], the so-called Pi∗S (T-allele of rs17580, in exon III), and Pi∗Z alleles (A-allele of rs28929474, in exon V) [6]. Here, SERPINA1 is linked to alpha 1-antitrypsin deficiency.