Co-inheritance of lithogenic ABCB4 and ABCG8 variants in a twin pair with juvenile onset gallstone disease and oral contraceptive and pregnancy aggravated cholestatic liver disease

Introduction: Rare variants of the ABCB4 gene encoding the phospholipid floppase MDR3 have been attributed to a wide spectrum of hepatobiliary syndromes spanning from neonatal cholestasis via gallstone disease (GD) and intrahepatic cholestasis of pregnancy (ICP) to liver cirrhosis. On the other hand, common polymorphisms within the genes encoding the heterodimeric cholesterol transporter ABCG5/8 have been associated with gallstone disease. Case report: Here we report on two female monozygotic twins who both underwent cholecystectomy at 13 and 15 years of age, respectively, for symptomatic GD but showed constantl…