Increased PiZ gene frequency for alpha 1 antitrypsin in patients with genetic haemochromatosis.

Original article


Elzouki AN, Hultcrantz R, Stal P, Befrits R, Eriksson S.

Department of Medicine, University of Lund, Malmo General Hospital, Sweden.

Gut. 1995 Jun;36(6):922-6.


The putative relationship between genetic haemochromatosis and PiZ alpha 1 antitrypsin deficiency was studied using a monoclonal antibody against the PiZ variant in 67 consecutive patients with genetic haemochromatosis seen at Karolinska Hospital and Huddinge University Hospital, Stockholm over a 10 year period. Three (4.5%) of the patients with haemochromatosis were found to be PiZ homozygotes (odds ratio = 82, confidence interval = 26, 256; p < 0.0001). The prevalence of the heterozygous (PiZ) phenotype was similar to that in the general population (p = 0.937). During the ascertainment period, liver biopsy was performed in 65 (97%) of the patients; 66% (2 of 3) of the PiZ homozygotes were found to have cirrhosis compared with 10% (6/59) of the non-carriers of the PiZ variant (p = 0.039). None of the homozygous or heterozygous alpha 1 antitrypsin deficient patients had developed hepatocellular carcinoma compared with 3.4% (2 of 59) of the non-PiZ gene carriers (p = 1.0). Two of those with the homozygous phenotype had developed severe emphysema. HLA typing was performed in 18 patients, 16 (89%) of whom manifested antigens known to be linked to haemochromatosis. There were no significant differences between the PiZ gene carriers and non-carriers in mean age at onset of disease, sex distribution, or HLA type. Two of the PiZ heterozygotes had plasma alpha 1 antitrypsin concentrations below the normal range, though the group mean was lower than that of the non-PiZ carriers (p = 0.0003). The data suggest that the presence of the PiZ allele for alpha1 antitrypsin deficiency, in a double dose, is associated with genetic haemochromatosis and may contribute to the earlier onset of cirrhosis in these patients, though it does not increase the risk of hepatocellular carcinoma. Keywords: Increased PiZ gene frequency for alpha 1 antitrypsin in patients with genetic haemochromatosis. Link/DOI: