Benign recurrent intrahepatic cholestasis type 2 is caused by mutations in ABCB11.

[benign recurrent intrahepatic cholestasis]

Progressive familial intrahepatic cholestasis (PFIC ) and benign recurrent intrahepatic cholestasis (BRIC ) are hereditary liver disorders ; PFIC is characterized by severe progressive liver disease whereas BRIC patients have intermittent attacks of cholestasis without permanent liver damage . Mutations in ATP 8 B 1 are present in PFIC type 1 and in a subset of BRIC patients . We hypothesized that a genetically distinct form of BRIC is associated with mutations in ABCB 11 . This gene encodes the bile salt export pump (BSEP ) and is mutated in PFIC type 2 .Patients from 20 families were included ; all had a normal ATP 8 B 1 sequence . Sequencing of all 27 coding exons including the splice junctions of ABCB 11 revealed 8 distinct mutations in 11 patients from 8 different families : one homozygous missense mutation (E 297 G ) previously described in PFIC 2 patients , 6 novel missense mutations , and one putative splice site mutation .In 12 families , no mutations in ATB 8 B 1 or ABCB 11 were detected . Pancreatitis is a known extrahepatic symptom in BRIC caused by ATP 8 B 1 mutations , but was not present in BRIC patients with mutations in ABCB 11 . In contrast , cholelithiasis was observed in 7 of 11 BRIC patients with mutations in ABCB 11 , but has not been described in ATP 8 B 1 -affected BRIC patients .Mutations in ABCB 11 are associated with BRIC , and consistent with the genetic classification of PFIC into 2 subtypes , we propose that this disorder be named BRIC type 2 .