We report on NR1H4 analysis in eight patients with progressive familial intrahepatic cholestasis (PFIC) and in eight women with either ICP and/or drug-induced cholestasis (DIC) in whom no disease causing mutation in ATP8B1, ABCB11 and/or ABCB4 were found.
Importantly, none of the PFIC1 mutants were detectable in the canalicular membrane of WIF-B9 cells, whereas all BRIC1/ICP mutants displayed the same cellular staining pattern as wild-type ATP8B1.
In conclusion, although the exon 2 and 7 changes may have functioned as risk alleles, ATP8B1 is probably not a major gene contributing to the occurrence of ICP.
Numerous studies have investigated the association of known cholestasis genes such as ABCB4 (also designated MDR3), ABCB11 ( BSEP) and ATP8B1 ( FIC1) with ICP.
The aim of this study was to investigate the genetic aetiology of intrahepatic cholestasis of pregnancy (ICP) and the impact of known cholestasis genes (BSEP, FIC1, and MDR3) on the development of this disease.