Cerebrotendinous xanthomatosis: reduced serum 26-hydroxycholesterol.

Abstract

Serum 26-hydroxycholesterol was quantitated by isotope dilution-mass spectrometry in normal individuals and in patients with cerebrotendinous xanthomatosis. In the normal individuals, the concentration of 26-hydroxycholesterol in serum ranged from 4.3 to 13.0 microgram/100 ml. In five patients with CTX, 26-hydroxycholesterol in serum ranged from 0 to 0.6 microgram/100 ml. The findings can be explained by reduced or absent mitochondrial C27 steroid 26-hydroxylase activity. The method is useful for detection of CTX and perhaps other disturbances of sterol and bite acid metabolism.