Abstract Arthrogryposis, Renal dysfunction and Cholestasis (ARC) syndrome is a rare inherited disorder caused by defects in the VPS33B trafficking protein, leading to impaired bile flow, progressive liver disease and early death. No effective treatments are currently available. Gene therapy offers a potential approach by restoring the missing VPS33B protein in liver cells. Here, we show that liver-targeted lentiviral gene therapy safely and effectively rescues key features of ARC syndrome in a m