ABCB4 variants in adult patients with cholestatic disease are frequent and underdiagnosed.

Background: Heterozygous ABCB4 variants are not routinely tested in adults with cholestasis because of their supposed rarity and high costs.

Methods: Nineteen adult patients presenting with unexplained cholestasis, and/or recurrent gallstones were included; genotyping was not done in five due to lack of health insurance approval.

Results: heterozygous ABCB4 variants were identified in seven patients, followed by cascade testing of 12 family members: one patient underwent liver transplantation at age 40 for end-stage liver disease; one had compensated cirrhosis; all symptomatic adults had gallstones, including four with low phospholipid-associated cholelithiasis; four had intrahepatic cholestasis of pregnancy; all children and one 54-year old female were asymptomatic.