Use of genetic analysis in adult cholestatic liver disease: lessons from progressive paediatric syndromes and cohort studies.

The increasing availability and decreasing costs of DNA sequencing have resulted in the re-grouping of rare, severe paediatric cases of progressive familial intrahepatic cholestasis (PFIC) with more frequent, later-onset cases of cholestasis (eg, intrahepatic cholestasis of pregnancy, benign recurrent intrahepatic cholestasis, low phospholipid-associated cholelithiasis) under the umbrella of genetic cholestasis. The common denominator is the presence of functional variants in the PFIC-associated genes, predominantly in ABCB4, ABCB11 and ATP8B1, which cause PFIC types 1-3. Several other congenital diseases such as Alagille syndrome and alpha1-antitrypsin deficiency comprise cholestatic pruritus as frequent symptoms.With the availability of intestinal bile acid transporter inhibitors (IBATi) as new and efficacious therapeutics for pruritus, the most debilitating symptom of PFIC, it is essential to envision their usefulness for patients with later-onset cholestatic liver disease suffering from pruritus.In this review, we summarise published studies on the genetic makeup of patients with paediatric, juvenile and adult-onset cholestasis, and discuss their findings with respect to genotype-specific treatment with IBATi, ursodeoxycholic acid, or alternative drugs. The aim is to provide an overview of the genetic variants likely to be encountered in future sequencing investigations of patients with cholestatic liver diseases, and how to translate this genetic information into personalised treatment recommendations.