Alpha-1 antitrypsin deficiency (AATD) is a hereditary condition caused by mutations in the SERPINA1 gene, encoding alpha-1 antitrypsin (AAT), an important antiprotease in the lungs that is primarily synthesized in the liver and released into the circulation. The Z mutant (p.E366K) is a common AAT allele. Individuals homozygous for the Z allele (Pi*ZZ) are susceptible to liver disease because of the accumulation of Z-AAT in the liver and to early onset emphysema because of the severe deficiency of AAT in circulation [1,2].
