Genetic factors in aetiology and phatogenesisof low gamma-glutamyltransferase cholestasis and hereditary jaundice

(English) Recent progress in understanding the molecular mechanism of hepatobiliary disorders enabled the improvement of diagnostic accuracy and promoted the study of the regulation of gene expression and its potential modifying factors. Current achievement in the field of genetically determined cholestatic disorders is well illustrated in this thesis, focused on low gamma-glutamyltransferase (γGT) cholestasis and hereditary jaundice. The study describes several distinct defects of hepatocyte transport system, characterises underlying mutations and their phenotypic consequences and, finally, extends these studies for detailed characterisation of ATP8B1 gene regulatory regions. Chapters related to low γGT cholestasis - characterise rare type of mutation associated with benign course of PFIC type I (formerly BRIC1) and explain the putative mechanisms of mutation origin. - provide extensive study of severe forms of ABCB11 deficiency (PFIC2) including genotype-phenotype correlations in 109 affected families, evaluation of the specific ABCB11 genotypes' impact on BSEP immunostaining and risk of hepatobiliary malignancy. - identify and characterise yet unknown regulatory regions of ATP8B1, a gene mutated in Progressive Familial Intrahepatic Cholestasis type I. The studies demonstrate the complex structure..