Cerebrotendinous Xanthomatosis (CTX) is a rare inherited lipid storage disorder caused by deficiency of mitochondrial sterol 27-hydroxylase, related to mutations in the CYP27A1 gene (Koyama et al., 2021; Federico and Gallus, 2022), ultimately leading to an increase of plasma and tissue cholestanol levels (Salen and Steiner, 2017). The gene discussed is CYP27A1; the disease is cerebrotendinous xanthomatosis.