Advanced liver disease associated with the rare alpha 1-antitrypsin phenotype IZ

We present the second case of advanced liver disease secondary to A1AT deficiency, due to the rare compound heterozygote PiIZ. In addition to the awareness of the pathogenic mutant I allele, the major learning points illustrated are (1) the mechanism by which A1AT mutant alleles cause hepatocellular injury, (2) the need to include diagnosis of A1AT deficiency in genotype analysis, and (3) the diagnostic limitations of a liver biopsy, particularly emphasizing the size of the tissue specimen.