Hydrophilic 7 beta-hydroxy bile acids, lovastatin, and cholestyramine are ineffective in the treatment of cerebrotendinous xanthomatosis.

We compared the effect of treatments with hydrophilic bile acids (ursodeoxycholic and ursocholic acids), cholestyramine, and lovastatin versus chenodeoxycholic acid in 4 patients with cerebrotendinous xanthomatosis (CTX). Bile acids and bile alcohols in plasma, bile, and urine before and after treatment were quantitated by gas-liquid chromatography. Untreated, all patients showed abnormal biliary bile acid composition: cholic acid (72.7%) and chenodeoxycholic acid (6.2%), and polyhydroxylated C(27)-bile alcohols (10.0%), and elevated plasma cholestanol levels. Treatment with hydrophobic chenodeoxycholic acid inhibited abnormal bile acid synthesis (virtual disappearance of C(27)-bile alcohols from plasma, bile, and urine and marked reduction of plasma cholestanol levels). Hydrophilic ursodeoxycholic and ursocholic acids did not inhibit abnormal bile acid synthesis, while cholestyramine increased abnormal bile acid synthesis (continued increased formation of polyhydroxylated C(27)-bile alcohols and further elevation of plasma cholestanol levels). Lovastatin did not affect abnormal bile acid synthesis or reduce plasma cholestanol levels. The results demonstrate that impaired side-chain oxidation in bile acid synthesis due to mutations of Cyp27 results in increased formation of polyhydroxylated C(27)-bile alcohols and cholestanol in CTX. Hydrophobic chenodeoxycholic acid, but not cholestyramine, lovastatin, or hydrophilic 7beta-hydroxy acids, inhibited the abnormal synthetic pathway. The role of chenodeoxycholic acid in downregulating abnormal bile acid synthesis in CTX is emphasized.

Two novel mutations in the sterol 27-hydroxylase gene causing cerebrotendinous xanthomatosis.

Cerebrotendinous xanthomatosis (CTX) is a rare recessive autosomal disease caused by mutations of the sterol 27-hydroxylase gene. Clinically, CTX is characterized by tendon xanthomas, cataracts and progressive neurological deficits. Because of the disruption of the 27-hydroxylase activity, CTX patients have elevated plasma levels of cholestanol, a by-product of abnormal bile acid synthesis. The present authors describe a female patient with CTX. The proband in this study presented with elevated cholestanol levels, markedly reduced mitochondrial 27-hydroxylase activity and altered bile acid composition. The 27-hydroxylase gene was analysed for mutations by polymerase chain reaction amplification of the exons and the splice-junction regions of the gene. The proband was found to be a compound heterozygote for two different mutations which have not been previously described: (1) a G --> A transition at nucleotide 455 that is responsible for converting a glycine to a glutamic acid residue at amino acid position 112 (G112E); and (2) a five-nucleotide deletion in exon 5 (from nucleotide 965 to 969) that is responsible for a shift in the reading frame and the insertion of a premature codon at position 296, and consequently, the synthesis of a truncated protein lacking the heme-binding and andrenodoxin-binding domains. Long-term (18-year) treatment of the proband with chenodeoxycholic acid (750 mg day-1) has been effective in preventing any progression of the disease.

Mutations in the sterol 27-hydroxylase gene (CYP27A) cause hepatitis of infancy as well as cerebrotendinous xanthomatosis.

Follow-up investigations were undertaken on a previously reported patient who had severe familial giant cell hepatitis in infancy associated with substantially increased urinary excretion of bile alcohol glucuronides. By the age of 11 years, he had developed a profile of cholanoids in plasma and urine that closely resembled the pattern seen in cerebrotendinous xanthomatosis (CTX). Sequencing of the sterol 27-hydroxylase gene (CYP27A) showed that he was homozygous for a deletion (525/526delG) that causes a frameshift and a premature stop codon. This genotype has previously been described in an adult female with classical symptoms of CTX (tendon xanthomata, cataracts and deteriorating cognitive function). A review of past medical histories of a group of patients with CTX revealed that prolonged neonatal cholestatic jaundice was common. The family histories also revealed fetal and neonatal deaths among siblings of patients with CTX. We conclude that defective activity of cholesterol 27-hydroxylase can lead to neonatal cholestatic jaundice ('hepatitis of infancy'), which may be self-limiting. After a latent period, however, progressive accumulation of cholesterol and cholestanol can lead to the xanthomata, neurodegeneration, cataracts and atherosclerosis that are typical of CTX.

Urinary bile alcohol profiles in healthy and cholestatic children.

BACKGROUND: Bile alcohols are normal constituents of urine. METHODS: To better understand bile alcohol profile in childhood, urinary specimens from 41 healthy children and 10 children with cholestasis, and 3 healthy adults, were analyzed by GLC and GC-MS. RESULTS: Five bile alcohols, 27-nor-5beta-cholestane-3alpha,7alpha,12alpha,24S,25R-pentol, 5beta-cholestane-3alpha,7alpha,12alpha,24S, 25-pentol, 5beta-cholestane-3alpha,7alpha,12alpha,24S,26-pentol, 5beta-cholestane-3alpha,7alpha, 12alpha,25,26-pentol, and 5beta-cholestane-3alpha,7alpha,12alpha,26,27-pentol were identified in all specimens. C(26)-Pentol was the most abundant constituent, constituting 29.5 to 65% of bile alcohols. Among healthy children (n=41), no significant relationship was seen between proportions of the C(26)-pentol and age, but older children (n=15, 6 to 14 years) showed a significantly greater mean percentage of the C(26)-pentol than young children (n=26, 0 to 5 years; 58.1+/-4.23% vs. 46.0+/-9.24%, p<0.001). In children with cholestatic liver diseases, the percentage of C(26)-pentol in urinary bile alcohols was significantly lower than age-matched controls. CONCLUSIONS: There is an increased composition of C(26)-pentol in older children and relatively decreased composition of C(26)-pentol in children with cholestatic liver diseases.

[Cerebrotendinous xanthomatosis]. / Cerebrotendineuze xanthomatosis.

A 24-year-old woman and a 13-year-old boy had suffered from diarrhoea, walking disorders, visual complaints and other complaints for many years. Once the suspicion of cerebrotendinous xanthomatosis (CTX) had been confirmed with biochemical and genetic tests and treatment with chenodeoxycholic acid had been started, the diarrhoea disappeared and the neurological symptoms lessened. CTX is a rare, autosomal recessive metabolic disease. The clinical hallmarks are: bilateral juvenile cataract, chronic diarrhoea, progressive neurological symptoms and signs, and tendon xanthomas. The phenotypic variability often hinders the clinical diagnosis. The biochemical diagnosis can be made by determining the serum cholestanol level and the excretion of urinary bile alcohols, followed by a mutation analysis. CTX is a treatable disease and therefore an early diagnosis is important.

Frontal lobe dementia with abnormal cholesterol metabolism and heterozygous mutation in sterol 27-hydroxylase gene (CYP27).

Of the primary dementing disorders that cause frontotemporal dementia, the best-known is Pick disease. We report on a 44-year-old woman with progressive frontal lobe dementia and spastic paraplegia. Examination revealed increased serum levels of cholestanol with abnormal cholesterol metabolism and a heterozygous mutation of the sterol 27-hydroxylase gene (CYP27). Biochemical findings were compatible with cerebrotendinous xanthomatosis (CTX); however, the clinical manifestations were very dissimilar. To our knowledge, a symptomatic carrier of this mutation among CTX patients has not been reported. We speculate that the present patient has a previously undescribed neurodegenerative disease related to abnormal cholesterol metabolism with this heterozygous mutation.

Cerebrotendinous xanthomatosis.

Cerebrotendinous xanthomatosis is a rare autosomal recessive lipid-storage disease caused by mutations in the sterol 27-hydroxylase gene. The accumulation of cholestanol in various tissues characterizes this disease. Diagnosis is based on determination of urinary bile alcohols. Therapy with chenodeoxycholic acid may arrest the progression of the disease. A 55-year-old woman presented with a slowly progressive paraparesia and two firm subcutaneous tumors over the knees. Her medical history revealed difficulty in standing and walking since infancy, bilateral juvenile cataracts, and mental retardation. Histopathologic examination of one subcutaneous tumor was consistent with tendinous xanthoma. Substantial elevation of urinary bile alcohols confirmed the diagnosis. Treatment with oral chenodeoxycholic acid was started, with only mild improvement of spasticity. Recognition of tendon xanthomas in a young patient with neurologic symptoms or cataracts (or both) is crucial to start early treatment and to avoid irreversible neurologic sequelae.

Structural and biosynthetic studies of a principal bile alcohol, 27-nor-5beta-cholestane-3alpha,7alpha,12alpha,24,25-pentol, in human urine.

The stereochemistry at C-24 and C-25 of 27-nor-5beta-cholestane-3alpha,7alpha,12alpha,24 ,25-pentol, a principal bile alcohol in human urine, and its biosynthesis are studied. Four stereoisomers of the C(26)-24,25-pentols were synthesized by reduction with LiAlH(4) of the corresponding epoxides prepared from (24S)- or (24R)-27-nor-5beta-cholest-25-ene-3alpha, 7alpha,12alpha,24-tetrol. The stereochemistries at C-25 were deduced by comparison of the C(26)-24,25-pentols with the oxidation products of (24Z)-27-nor-5beta-cholest-24-ene-3alpha,7alpha, 12alpha-triol with osmium tetraoxide. On the basis of this assignment, the principal bile alcohol excreted into human and rat urine was determined to be (24S,25R)-27-nor-5beta-cholestane-3alpha,7alpha, 12alpha,24,25-pentol, accompanied by a lesser amount of (24R, 25R)-isomer. To elucidate the biosynthesis of the C(26)-24,25-pentol, a putative intermediate, 3alpha,7alpha, 12alpha-trihydroxy-27-nor-5beta-cholestan-24-one, derived from 3alpha,7alpha, 12alpha-trihydroxy-24-oxo-5beta-cholestanoic acid by decarboxylation during the side-chain oxidation of 3alpha,7alpha, 12alpha-trihydroxy-5beta-cholestanoic acid, was incubated with rat liver homogenates. The 24-oxo-bile alcohol could be efficiently reduced to yield mainly (24R)-27-nor-5beta-cholestane-3alpha,7alpha, 12alpha,24-tetrol. If a 25R-hydroxylation of the latter steroid occurs, it should lead to formation of (24S,25R)-C(26)-24,25-pentol. Now it has appeared that a major bile alcohol excreted into human urine is (24S,25R)-27-nor-5beta-cholestane-3alpha,7alpha, 12alpha, 24, 25-pentol, which might be derived from 3alpha,7alpha, 12alpha-trihydroxy-27-nor-5beta-cholestan-24-one via (24R)-27-nor-5beta-cholestane-3alpha, 7alpha,12alpha,24-tetrol.

Presence of diarrhea and absence of tendon xanthomas in patients with cerebrotendinous xanthomatosis.

BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disorder of bile acid synthesis. A diagnosis of CTX should be considered in patients with premature bilateral cataracts, intractable diarrhea, neurological signs and symptoms, and tendon xanthomas, especially in the Achilles tendons. The prevalence of these signs and symptoms increases with age. OBJECTIVES: To investigate signs and symptoms, age at onset, and age at diagnosis in 32 patients with biochemically and genetically confirmed CTX, and to compare this clinical spectrum with reports in the literature. METHODS: Retrospective analysis of records of all patients with CTX at our hospital (27 adults and 5 children). After a MEDLINE search in the English, French, and German literature, 181 patients with CTX (165 adults and 16 children) were identified worldwide. RESULTS: Of our 32 patients with CTX, 31 (97%) had cataracts and neurological signs and symptoms, predominantly pyramidal signs (26 [81%]); 21 (66%) had low intelligence and 18 (56%) had cerebellar signs. Only 13 (41%) had visible or palpable tendon xanthomas at the time of diagnosis. In total, 16 patients (50%) had chronic, intractable diarrhea that started in childhood. These findings were in contrast with the literature, where tendon xanthomas were reported in 89% and diarrhea in only 2 patients. CONCLUSIONS: We believe that CTX is underdiagnosed worldwide. We recommend that the presence of 2 of the 4 clinical hallmarks of CTX prompt thorough metabolic screening, including determination of urine bile alcohol excretion and serum cholestanol level, because CTX is a treatable disease.

Urinary bile alcohol profile in infants with intrahepatic cholestasis: identification of 5beta-cholestane-3alpha,7alpha,24,25-tetrol.

Urinary bile acids and bile alcohols were examined in six infants aged between 1 and 6 mo who had intrahepatic cholestasis. Following extraction, hydrolysis and solvolysis, cholanoids were analysed by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. The relative ratio of the urinary excretion of bile alcohols to bile acids was very low (0.07-0.22) in three patients with mild to severe cholestasis, whereas the urinary excretion of bile alcohols was 2-4 times greater than that of the total bile acids in three patients with slight cholestasis. The urinary bile alcohol spectrum in infants appears to be quite different from that in adults. Although the major bile alcohol was 27-nor-5beta-cholestane-3alpha,7alpha,12alpha,24 ,25-pentol, comprising more than 50% of total urinary bile alcohols in healthy adults, it accounted for only 35% of total urinary bile alcohols in our patients. In addition, bile alcohols carrying chenodeoxycholic acid type nucleus were detected in our patients by comparison of the retention times and mass spectra with those of authentic standards. The presence of 5beta-cholestane-3alpha,7alpha,24,25-tetrol confirmed for the first time in this study may represent an alternative pathway for chenodeoxycholic acid biosynthesis via a "25-hydroxylation pathway" in early life.

Treatment and follow-up of children with cerebrotendinous xanthomatosis.

UNLABELLED: The clinical spectrum and the effects of treatment over a period of 5 years in five children with cerebrotendinous xanthomatosis (CTX) are described. In all children biochemical, neuroradiological, and neurophysiological studies were done. CTX was diagnosed and effects of therapy were evaluated by determination of the serum cholestanol/cholesterol ratio (CCR) and the urinary excretion of bile alcohols. All children were treated with chenodeoxycholic acid (15 mg/kg/day) in three divided oral doses. Diarrhoea and juvenile cataract were the main clinical features. Psychomotor retardation, pyramidal and cerebellar signs were also found. After starting treatment, biochemical abnormalities normalized and diarrhoea disappeared. After 1 year of therapy there was no further delay in motor development, and in three children the intelligence quotient improved. EEG abnormalities disappeared. After 5 years of therapy the children are in a stable clinical condition. CONCLUSION: The clinical, biochemical and neurophysiological abnormalities in five children with CTX showed a remarkable improvement after starting treatment with chenodeoxycholic acid. The early diagnosis of CTX and the start of treatment with chenodeoxycholic acid has prevented neurological deterioration for a period of 5 years.

Chronic diarrhoea as a dominating symptom in two children with cerebrotendinous xanthomatosis.

The objective of this study was to describe diarrhoea as a dominating symptom of cerebrotendinous xanthomatosis (CTX), a lipid storage disease, and investigate its cause. Two children with chronic diarrhoea as the dominating symptom of CTX are presented. Before and after therapy with orally administered chenodeoxycholic acid (15 mg kg-1 24 h, in three divided doses) bile alcohol excretion in urine, serum cholestanol level, serum bile acid patterns and faecal bile acids were measured. All routine gastro-intestinal investigations before therapy were normal. Diarrhoea ceased immediately after starting treatment with chenodeoxycholic acid. Abnormal bile alcohol excretion in urine decreased rapidly during the first days and elevated serum cholestanol level normalized in 2 years. We postulate the presence of bile alcohols in the lumen of the gut as most likely cause for diarrhoea in CTX, since the rapid decrease of bile alcohol excretion is associated with prompt cessation of diarrhoea after starting treatment with chenodeoxycholic acid.

Familial giant cell hepatitis with low bile acid concentrations and increased urinary excretion of specific bile alcohols: a new inborn error of bile acid synthesis?

A 9-wk-old infant with familial giant cell hepatitis and severe intrahepatic cholestasis had low plasma concentrations of chenodeoxycholic acid and cholic acid and elevated plasma concentrations of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24 zeta-tetrol, and 5 beta-cholest-24-ene-3 alpha,7 alpha,12 alpha-triol. Analysis of the urine by fast atom bombardment mass spectrometry and by gas chromatography-mass spectrometry after treatment with Helix pomatia glucuronidase/sulfatase showed that the major cholanoids in urine were the glucuronides of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24S,25-pentol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol, and 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24 zeta-tetrol. These results are consistent with an inborn error of the 25-hydroxylase pathway for bile acid synthesis, specifically one of the enzymes responsible for conversion of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24S,25-pentol to cholic acid and acetone. Treatment with chenodeoxycholic acid was tried on two occasions. On the first it appeared to precipitate a rise in bilirubin, on the second the liver function tests improved and the improvement was maintained when the treatment was modified to a combination of chenodeoxycholic acid and cholic acid and finally, cholic acid alone. Despite the normalization of liver function tests, a liver biopsy at 1.25 y showed an active cirrhosis. Nonetheless, the child is thriving at the age of 3.5 y, whereas an affected sibling died at 13 mo.

Biochemical studies of inherited diseases related to abnormal cholesterol metabolism. II: Absence of unusual C28 and C29 bile acid homologs in bile and urine of sitosterolemia.

Bile acids, bile alcohols and sterols excreted in bile and urine from a patient with sitosterolemia were studied. Glycine- and taurine-conjugated cholic acid, deoxycholic acid and chenodeoxycholic acid were identified as the major constituents of both the bile and urine. Lesser amounts of unconjugated cholic acid and 3 alpha, 7 alpha, 12 alpha, 24-tetrahydroxy-5 beta-cholestan-26-oic acid were found in the bile, but cholic acid was the only unconjugated bile acid in the urine. Relatively high proportions of campesterol and sitosterol compared to cholesterol were excreted in the bile, while cholesterol was the only sterol detected in the urine. Bile alcohols were not detected in the bile, but the following bile alcohols were excreted in the urine as glucurono-conjugates: 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol; 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25-pentol; 5 beta-cholestane-3 alpha,7 alpha,12 alpha,23,25-pentol; 5 beta-cholestane- 3 alpha,7 alpha,12 alpha,24,25-pentol; 5 beta-cholestane- 3 alpha,7 alpha,12 alpha,25,26-pentol. In neither the bile nor urine, were C28 and C29 bile acid homologs detected. Thus, the main route for the excretion of plant sterols in sitosterolemia is thought to be secretion into the bile as neutral sterols.

Capillary gas-liquid chromatographic separation of bile alcohols.

Gas-liquid chromatographic separation of C23, C24, C25, C26, and C27 bile alcohols with either 3 alpha, 7 alpha-dihydroxylated or 3 alpha, 7 alpha, 12 alpha-trihydroxylated ring system on two capillary columns, CP-Sil-19 CB and CP-Sil-5 CB, is described. Bile alcohols with two ring hydroxyl groups at 3 alpha- and 7 alpha-positions consistently showed larger retention times on CP-Sil-19 CB columns and smaller retention times on CP-Sil-5 CB columns than the corresponding bile alcohols with three ring hydroxyl groups at 3 alpha-, 7 alpha-, and 12 alpha-positions. Resolutions of all bile alcohols were better on CP-Sil-19 CB columns; however, we hope that the gas-liquid chromatographic characteristics on the two columns will be useful for better identification of bile alcohols in biological fluids.

Identification of (23S)-5 alpha-cholestane-3 alpha,7 alpha,12 alpha,23,25-pentol in urine of patients with cerebrotendinous xanthomatosis.

This paper describes the identification of a new bile alcohol possessing the 5 alpha-cholestane structure that was found in the urine of patients with cerebrotendinous xanthomatosis. The urine samples were extracted with reversed-phase resin, treated with beta-glucuronidase, and separated on silica gel and reversed-phase column chromatography. The new bile alcohol isolated was the second component of the urinary bile alcohols and was identified as (23S)-5 alpha-cholestane-3 alpha,7 alpha,12 alpha,23,25-pentol by means of gas-liquid chromatography/mass spectrometry and nuclear magnetic resonance spectroscopic studies.

Reduction of urinary bile alcohol excretion and serum cholestanol in patients with cerebrotendinous xanthomatosis after oral administration of deoxycholic acid.

Deoxycholic acid and chenodeoxycholic acid were administered alternately to four patients with cerebrotendinous xanthomatosis. During this oral therapy serum cholestanol and urinary bile alcohols were determined. Both showed a marked decrease after the start of the two different therapies. It can be concluded that not only chenodeoxycholic acid but also deoxycholic acid is able to suppress endogenous human bile acid synthesis, which is in accordance with other experiments describing the effect of feeding of various bile acids on endogenous bile acid synthesis.