Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by a mutation in the cytochrome P450 family 27 subfamily A member 1 (CYP27A1) gene, leading to abnormal accumulation of cholesterol and its derivatives in tissues, particularly in the central nervous system, eyes, tendons, and blood vessels. Here, CYP27A1 is linked to cerebrotendinous xanthomatosis.