[Cerebrotendinous xanthomatosis].

Cerebrotendinous xanthomatosis (CTX) is a rare familial lipid storage disease caused by defective bile acid synthesis. As a result, cholestanol, a derivative of cholesterol, is accumulated by virtually every tissue, predominantly by the nervous system, xanthomas and bile. Clinically, progressive neurologic dysfunction, tendon xanthomas, cataracts, osteoporosis and atherosclerosis are commonly found. Replacement therapy with chenodeoxycholic acid (750 mg/day), a primary bile acid, which is almost absent from the bile in CTX, reduces elevated cholestanol synthesis and concentrations and improves neurologic function in this disease.