Heterozygous Inactivation of the Nuclear Receptor PXR/NR1I2 in a Patient With Anabolic Steroid-Induced Intrahepatic Cholestasis

Abstract

Introduction: The incidence of liver damage due to steroid consumption is increasing due to the omnipresence of the idealized body image and the widespread availability of drugs via the Internet. The genetic factors underlying individual susceptibility are not presently known. Case Presentation: A male patient developed cholestatic liver injury two weeks after a two-month course of anabolic steroids. Next-generation sequencing (NGS) of 24 cholestasis-related genes revealed a heterozygous two-basepair deletion in exon 1 of the pregnane X receptor gene (PXR). Serum bile salt levels showed marked imbalances, strongly resembling the changes observed in patients with biliary obstruction. Conclusions: This case of PXR haploinsufficiency reveals transcriptional regulatory functions activated in the liver under xenobiotic stress by steroids, which appear to require two functional copies of the nuclear receptor gene. Deranged bile salt levels outline the central role of PXR in bile acid synthesis, modification, and export.