In this study, the UNC researchers collaborated with an international team of scientists to compile the largest number of samples ever from cystic fibrosis patients with severe liver disease. The study was initially conducted in 124 cystic fibrosis patients with severe liver disease and 843 cystic fibrosis patients without liver disease. The team evaluated nine sequence variants in five genes that previous studies had suggested might be associated with liver disease.

They found that more cystic fibrosis patients with liver disease had a particular version of the SERPINA1 gene -- called the Z allele - than patients without liver disease, indicating that the gene variant plays a role in the development of this ailment. The researchers confirmed their results in a separate set of cystic fibrosis patients, 136 with liver disease and 1088 without.

According to lead study author Jaclyn R. Bartlett, Ph.D., discovering such risk factors will enable clinicians to identify cystic fibrosis patients who may be predisposed to develop liver disease. "We also hope that further research will show how the presence of this particular gene affects the liver on a molecular level in cystic fibrosis patients," said Bartlett, a research associate scientist at UNC.

Aided by their international collaborators, the researchers are now searching for genetic modifiers associated with other complications of cystic fibrosis, including lung disease, intestinal obstruction and diabetes.

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