Variable degree of liver involvement in siblings with PiZZ alpha-1-antitrypsin deficiency-related liver disease.

PiZZ alpha-1-antitrypsin deficiency is the commonest genetic cause of chronic liver disease, but only 10-15% of PiZZ individuals develop liver disease in childhood. Studies have demonstrated varying patterns of disease progression within siblings with the PiZZ phenotype. We retrospectively analysed the case-notes of all patients diagnosed with PiZZ A1ATD between 1978-2002 and compared the pattern of liver disease between affected siblings. We identified 29 families with more than 1 child with the PiZZ phenotype. Twenty-one (72%) PiZZ siblings of the 29 probands had liver disease, which was concordant for severity in 6 (29%), while 8 (28%) had no liver involvement. Five of 7 children requiring liver transplantation had siblings with no persistent liver dysfunction. This study suggests that there is a variable degree of liver involvement in siblings with PiZZ A1ATD-related liver disease and environmental and/or other genetic factors must be involved in determining disease severity.