ABCB4

ABCB4 is an ATP-dependent phosphatidylcholine floppase concentrated in the apical canalicular membrane of hepatocytes. Its two transmembrane and nucleotide-binding halves couple ATP utilization to movement of phosphatidylcholine from the cytosolic to the exoplasmic membrane leaflet. Bile salts extract the exposed phospholipid into bile, where it contributes to mixed lipid assemblies that reduce detergent injury and support cholesterol solubilization. Phosphatidylcholine is its established physiological lipid substrate; limited drug-substrate interactions also occur. Biallelic loss of functional ABCB4 causes progressive familial intrahepatic cholestasis type 3, and reduced expression, trafficking or transport competence can produce other cholestatic phenotypes.

Disorders

Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.

An entry matches when ClinGen's MONDO disease is the entry's own disease term, a subtype term, or an exact-match mapping. An amber status marks an entry ClinGen supports the gene for (Definitive, Strong or Moderate) whose own record does not type it. A Limited, Disputed or Refuted tier on such an entry is not a gap.

• cholestatic_liver_injury via Progressive Familial Intrahepatic Cholestasis