Serum bile acid profiles in cerebrotendinous xanthomatosis.

Non-sulfated bile acid concentrations in sera of 10 cases of cerebrotendinous xanthomatosis (CTX) were determined by mass fragmentography. Total bile acid (TBA) in serum was 0.492 +/- 0.436 microgram/ml (mean +/- SD) which was significantly lower than that (1.481 +/- 0.571) in healthy control sera. Cholic acid was 0.342 +/- 0.291 microgram/ml and was the dominant bile acid, which constituted 69.5% of TBA in serum. Chenodeoxycholic acid was 0.111 +/- 0.133 microgram/ml being a minor component in CTX sera, although it was the major bile acid in healthy control sera. Other bile acids such as deoxycholic acid, lithocholic acid and ursodeoxycholic acid were scarcely detected. Subnormal TBA level and deranged bile acid composition in CTX sera may reflect the defect of bile acid biosynthesis in CTX patients. Determination of serum bile acid may be useful in the diagnosis of CTX.