Figure 1

Metabolic pathway involved in cerebrotendinous xanthomatosis (CTX; modified from Chales and Bjorkhem [ [10], [74]] ). Due to a mutation in the CYP27A1 gene, cholesterol cannot be converted into bile acids, but is instead converted into cholestanol and bile alcohol. Providing chenodeoxycholic acid exogenously has a negative feedback effect that reduces synthesis of bile acid, thus preventing accumulation of cholestanol.