Effect of nitisinone (NTBC) treatment on the clinical course of hepatorenal tyrosinemia in Québec

► A 25-year record of hepatorenal tyrosinemia (HT1) in Québec is presented. ► 71% of non-nitisinone treated HT1 patients required liver transplantation (median age, 26 m). ► Nitisinone treatment abolished the acute complications of HT1 and reduced HT1-related deaths. ► Some late-treated patients, who had liver findings before treatment, required transplantation. ► Screened newborns with early nitisinone treatment had no detectable liver disease after ≥ 5 y.