Phosphatidylcholine translocator ABCB4 (EC 188.8.131.52) (ATP-binding cassette sub-family B member 4) (Multidrug resistance protein 3) (P-glycoprotein 3) [MDR3] [PGY3]
The phospholipidfloppase MDR3 (gene symbol: ABCB4) is expressed in the canalicular membrane of hepatocytes and mediates the biliary excretion of phosphatidylcholine, which is required for the formation of mixed micelles in bile. Several mutations of ABCB4 have been identified, which cause cholestatic liver diseases of varying severity including progressive familial intrahepatic cholestasis type 3 (PFIC-3), intrahepatic cholestasis of pregnancy (ICP) and the low phospholipid associated cholelithiasis syndrome (LPAC). Here, we report on four new (S1076N; L 23Hfs16X; c.286 1G > A; Q 1181E) and one known (S27G) MDR3 mutations in eight patients of three families. The patients presented with a wide spectrum of liver diseases. The clinical presentation and decisive laboratory findings or the association to a trend-setting family history led to the identification of the genetic background in these patients. Even the same mutation may be associated with varying disease progression.
- ATP Binding Cassette Transporter, Subfamily B
- Child, Preschool
- Cholestasis, Intrahepatic
- Genetic Predisposition to Disease
- Genetic Variation