Alpha-1 antitrypsin deficiency (AATD) is an inherited genetic disorder that is most commonly caused by a G-to-A point mutation in the SERPINA1 gene. This mutation results in the production of insufficient levels of circulating M-AAT protein, which protects the lungs from proteolytic enzymes, and aggregation of misfolded Z-AAT protein in hepatocytes. This leads to lung and liver disease. Individuals with AATD have Z mutations on both alleles, known as the PiZZ genotype.
Augmentation therapy via delivery of functional AAT protein is currently the only treatment option for AATD lung disease and requires weekly intravenous infusions. There are no treatments for AATD liver disease, other than liver transplantation.