Novel single nucleotide polymorphisms of the cytokeratin 19 pseudogene are associated with primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is characterized by chronic inflammation and destruction of intra-hepatic bile ducts. However, the pathogenesis of PBC has not been fully delineated. We examined whether patients with PBC harbor genomic mutations of the cytokeratin 19 (CK19) gene since that gene is specifically expressed in biliary epithelial cells. Thirty-six patients with PBC, 26 patients with other liver diseases, and 36 healthy volunteers were enrolled in this study, but there were no significant differences in the genomic sequence of the CK19 gene between those groups. On the other hand, novel single nucleotide polymorphisms (SNPs) of the CK19 pseudogene, C341T, T524G and A754G, were frequently detected in PBC patients. These results suggest that those novel SNPs of the CK19 pseudogene may be associated with PBC and may prove useful for predicting susceptibility to PBC.