One of the most common inherited disorders among caucasians. Incidence is 1 per 2-7000 population. The phenotypic variations in AAT gene is expressed as the Protease inhibitor (Pi) alphabetical nomenclature. The Pizz variant most often characterizes the ATT deficiency state. Among Pizz infants with jaundice 25% will experience cirrhosis within the first decade of life, 25% will show persistent liver enzyme elevation progressing to cirrhosis in the second decade, 25% will resolve the biochemical change completely and show only mild fibrosis on biopsy. The liver injury in all these cases is probably attributed to release of proteases.
Liver transplantation normalizes serum ATT levels and hence none of the transplanted patients develop lung injury and emphysema.