Varied phenotypic presentation of congenital bile acid synthesis defect type 2 in a set of first-degree relatives with the same genetic mutation.

Bile acid synthesis disorders represent a rare subset of cholestatic conditions that, if unrecognised, may progress to end-stage liver disease requiring transplantation. These disorders result from deficiencies in one of the 17 enzymes involved in the conversion of cholesterol into primary bile acids. We present a case series of three first-degree relatives diagnosed with congenital bile acid synthesis defect type 2 (AKR1D1 deficiency), a disorder characterised by impaired steroid 5β-reductase activity. After initiating cholic acid, all patients demonstrated significant clinical improvement.