• Bile Flow
• Cholestatic Liver Diseases
• Bile Acid
• Pharmacotherapy
• Mutations

Paediatric cholestasis is a rare but devastating group of diseases that usually manifest in infancy or childhood by impaired bile secretion, due to either primary or secondary alterations affecting the liver secretory machinery, and that may progress to cirrhosis and liver failure. Although there is resemblance in clinical symptoms, the cause of these diseases can be completely different, which is important because it determines, among others, the response to treatment. For a specific subgroup of cholestatic diseases, namely those associated with canalicular transport defects, our pathophysiological understanding has been increased enormously over the last decade. In parallel, treatment options have been developed,1 and the article by Gordo–Gilart et al 2 yet takes another step forward.

Several transport proteins located at the canalicular membrane of hepatocytes are required to maintain the correct secretory function of the liver (figure 1). A crucial role is played by a member of the superfamily of ATP-binding cassette proteins, the bile salt export pump ABCB11 (formerly designated as BSEP), which accounts for the active transport of bile acids into the canalicular lumen and, hence, the generation of the osmotic gradient that drives canalicular bile flow.3 The correct functioning of this and other transporters requires specific physical-chemical characteristics at the canalicular membrane, where they are inserted, which are dependent, in part, on …