Identification of interacting modifier loci of liver fibrosis in Abcb4/Mdr2 deficient mice

Functional variants in the ATP-binding cassette transporter gene ABCB4, have been identified in various cholestatic liver diseases, including progressive intrahepatic familial cholestasis. Phenotypic presentations of patients harbouring ABCB4 mutations differ markedly, and to date no modifier loci have been identified in human cohorts. We recently reported a single modifier locus on chromosome (chr) 4 (Grünhage et al. AASLD 2008) in a backcross of Abcb4 deficient mice. We now analysed these mice with regards to locus interactions influencing liver fibrosis.Fibrosis was monitored in an F2 cross of fibrosis-suscep…