Diagnosis and disease–modifying treatments of cerebrotendinous xanthomatosis

Abstract

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disorder caused by mutations in the CYP27A1 gene, which encodes the mitochondrial enzyme sterol 27–hydroxylase.

Decreased sterol 27–hydroxylase activity results in impaired bile acid synthesis, leading to a reduced production of bile acids, especially chenodeoxycholic acid (CDCA), as well as elevated serum cholestanol. Clinical presentation is characterized by neonatal jaundice or cholestasis, refractory diarrhea, juvenile cataracts, tendon xanthomas, osteoporosis, coronary heart disease, and progressive neuropsychiatric disturbances. Although replacement treatment with CDCA in the early stage of the disease has been reported to improve or even prevent clinical symptoms of CTX, after significant neurological pathology is established, the effect of the treatment is limited. Therefore, early diagnosis and subsequent treatment initiation are essential in CTX.