Simplified determination of cholestanol in serum by gas-liquid chromatography: biochemical diagnosis of cerebrotendinous xanthomatosis.

Cholestanol (5 alpha-cholestan-3 beta-ol) in human serum was determined by gas-liquid chromatography after removal by epoxidation of cholesterol which is present in amounts about 400 times those of cholestanol and disturbs the accurate determination of minor sterols in serum. Epicholestanol (5 alpha-cholestan-3 alpha-ol) was used as an internal standard. By this method the cholestanol content in sera of 7 patients with cerebrotendinous xanthomatosis was determined. The cholestanol levels in those sera were significantly higher than those of normal subjects and the present method proved to be useful in a biochemical diagnosis of cerebrotendinous xanthomatosis.