Accumulation of 7α-hydroxy-4-cholesten-3-one and cholesta-4,6-dien-3-one in patients with cerebrotendinous xanthomatosis: Effect of treatment with chenodeoxycholic acid

✍ Scribed by Ingemar Björkhem; Sverre Skrede; Marie S. Buchmann; Cara East; Scott Grundy

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 580 KB
• Volume: 7
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840070210

✦ Synopsis

Evidence was recently presented that an essential part of the accumulation of cholestanol in patients with cerebrotendinous xanthomatosis is due to acceleration of a novel pathway, involving ?a-hydroxylated intermediates in bile acid biosynthesis as precursors (J. Clin. Invest. 1986; 75:448-456). Such intermediates accumulate in patients with cerebrotendinous xanthomatosis due to lack of the mitochondrial 26-hydroxylase involved in the major pathway for bile acid biosynthesis. The new pathway may involve the following steps: 7a-hydroxycholesterol+7a-hydroxy-4-cholesten-3-0~1- cholesta-4,6-dien-3-on~4-cholesten-3-one-*cholestanol.

Accurate methods have been developed for asmay of 7a-hydroxy-4-cholesten-3-one and cholesta-4,6-dien-3one in serum, based on isotope dilution-mass spectrometry. The serum levels of 7a-hydroxy-4-cholesten-3-one as well as those of cholesta-4,6-dien-3-one were found to be markedly elevated in the three patients with cerebrotendinous xanthomatosis. Treatment of two of the patients with chenodeoxycholic acid reduced the serum levels of the two steroids by more than 80%. The concentration of cholestanol was reduced by 72% in one patient and by 48% in the other.

The possibility is discussed that accumulation of cholestanol in patients with cerebrotendinous xanthomatosis is secondary to accumulation of 7a-hydroxy-4-cholesten-3-one and cholesta-4,6-dien-3-one.

The major symptoms of the rare, inherited disease cerebrotendinous xanthomatosis (CTX) are due to accumulation of cholesterol and cholestanol in the central nervous system and other tissues (1, 2). An increased rate of synthesis of cholestanol contributes to the accumulation of this steroid (3). Recently, we presented evi-