Professor Minoru Nakamura of theNagasaki UniversityGraduate School of Biomedical Sciences and his colleagues identified genes conferring susceptibility to primary biliary cirrhosis, for the first time in the world, in the Japanese populations.

A nation-wide research team, which is directed by Professor Minoru Nakamura of the Nagasaki University Graduate School of Biomedical Sciences, has performed genome-wide association study (GWAS) using DNA samples of 1500 Japanese patients with primary biliary cirrhosis and 1200 Japanese healthy volunteers, and successfully identified for the first time in the world the two disease-susceptibility genes which are involved in the onset of primary biliary cirrhosis in the Japanese populations

Primary biliary cirrhosis is a relatively rare cholestatic liver disease of unknown etiology that mostly affects middle-aged and elderly women (approximately 50,000 to 60,000 individuals are estimated to be affected in Japan). Since fatal jaundice and liver failure is induced with the progression of the disease, primary biliary cirrhosis is classified as an intractable disease in which no lifesaving measures are available except liver transplantation.

The identified TNFSF15 and POU2AF1 genes play critical roles in the maturation and differentiation of immunocompetent cells such as T-lymphocytes and B-lymphocytes. This study has revealed that individual differences in these genes (genetic polymorphisms) are associated with the onset of primary biliary cirrhosis in the Japanese populations.
Further study will facilitate the development of radical treatment for primary biliary cirrhosis by targeting these gene-products.

The results of this research were published in American Journal of Human Genetics (20 September 2012, online version).

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