Cerebrotendinous 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.     

Measuring health status using the Health Utilities Index: agreement between raters and between modalities of administration

The aim of this study was to evaluate interrater and intermodality agreement in assessing health status using the Health Utilities Index. A random sample from a Dutch cohort of 14-year-old Very Low Birth Weight children and their parents were invited to participate in a face-to-face (n = 150) or telephone (n = 150) interview. All 300 participants were also sent a questionnaire by mail. Response rate was 68%. Interrater and intermodality agreement were high for the physical HUI3 attributes and poor for the psychological attributes. Children and parents reported more dysfunction in the psychological attributes when interviewed than when completing the mailed questionnaire. High agreement on the physical attributes may have resulted from the fact that hardly any dysfunction was reported in these attributes, and poor agreement in the psychological attributes may have been a result of the fact that in these attributes much more dysfunction was reported. In measuring children's health status using the HUI3, the results and their interpretation vary with the source of information and the modality of administration. For maximum comparability between studies, written self-report questionnaires seem the preferred option.     

Neuroleptic malignant syndrome during zuclopenthixol therapy in X-linked cerebral adrenoleukodystrophy

An 8 year-old boy with X-ALD under treatment with simvastatin developed a severe adverse reaction when the dose of his other medication, zuclopenthixol was increased. Both drugs were withdrawn after a diagnosis of neuroleptic malignant syndrome was made.     

Nonmuscular involvement in merosin-negative congenital muscular dystrophy

The spectrum of nonmuscular involvement in six children with merosin-negative congenital muscular dystrophy is described. In all children, biochemical, neuroradiologic, cardiac, and neurophysiologic studies were performed. Cerebral structures that were myelinated at gestation, including internal capsule, corpus callosum, brainstem, and cerebellar white matter, demonstrated no abnormalities, whereas the periventricular and subcortical white matter, which were myelinated in the first postnatal year, demonstrated signs of leukoencephalopathy. Cerebrospinal fluid analysis revealed an elevated albumin cerebrospinal fluid to serum ratio in the younger children. Electroencephalogram results were abnormal in the two elder children. One child suffered from congestive cardiomyopathy. The increase in nerve conduction velocity in these children over the years lagged behind those of healthy patients, pointing to a demyelinating neuropathy. We conclude that in merosin-negative congenital muscular dystrophy patients, nonmuscular involvement includes the central and peripheral nervous system and the heart. The pattern of myelination of the brain and nerve conduction slowing suggests a myelination arrest. Merosin deficiency can give rise to a congestive cardiomyopathy, which is of no clinical relevance in the majority of children.     

Elevated cholesterol precursors other than cholestanol can also be a hallmark for CTX

Cerebrotendinous xanthomatosis (CTX) is an inborn error of bile acid synthesis in which hepatic conversion of cholesterol to cholic and chenodeoxycholic acids is impaired. Patients have abnormal bile alcohols in urine, normal to increased plasma cholesterol concentrations and increased concentrations of plasma cholestanol. Little is known about cholesterol precursors in CTX, however. We studied cholesterol and phytosterol profiles in two siblings with CTX during follow-up. While cholesterol concentrations were low in both patients, plasma cholestanol was 6-fold higher compared to control values. In addition, both siblings had a more than 100-fold increase in 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC). Lathosterol, lanosterol and sitosterol were increased in both patients while concentrations of desmosterol and campesterol were normal. In addition, plasma lathosterol/cholesterol ratios were significantly elevated. After treatment with chenodeoxycholate, both patients showed a marked decrease in cholestanol, 7DHC, 8DHC, lathosterol, lanosterol and sitosterol. In addition, the lathosterol/cholesterol ratio normalized, indicating that overall cholesterol synthesis was sufficiently suppressed. This study shows that elevated cholesterol precursors, other than cholestanol, can be a hallmark for CTX.