Coronary heart disease in a patient with cerebrotendinous xanthomatosis

SEA 2024 Standards for Global Control of Vascular Risk

One of the objectives of the Spanish Society of Arteriosclerosis is to contribute to the knowledge, prevention and treatment of vascular diseases, which are the leading cause of death in Spain and entail a high degree of disability and health expenditure. Atherosclerosis is a multifactorial disease and its prevention requires a global approach that takes into account the associated risk factors. This document summarises the current evidence and includes recommendations for patients with established vascular disease or at high vascular risk: it reviews the symptoms and signs to evaluate, the laboratory and imaging procedures to request routinely or in special situations, and includes the estimation of vascular risk, diagnostic criteria for entities that are vascular risk factors, and general and specific recommendations for their treatment. Finally, it presents aspects that are not usually referenced in the literature, such as the organisation of a vascular risk consultation.

Disorders with prominent posterior fossa involvement

Inherited white matter disorders include a wide range of disorders of various origins with distinct genetic, pathophysiologic, and metabolic backgrounds. Although most of these diseases have nonspecific clinical and radiologic features, some display distinct clinical and/or imaging (magnetic resonance imaging, MRI) characteristics that might suggest the causative gene. Recent advances in genetic testing allow assessing gene panels that include several hundred genes; however, an MRI-based diagnostic approach is important to narrow the choice of candidate genes, particularly in countries where these techniques are not available. Indeed, white matter disorders with prominent posterior fossa involvement present specific MRI (and clinical) phenotypes that can directly orient the diagnosis. This chapter describes the main genetic disorders with posterior fossa involvement and discusses diagnostic strategies.

Pathophysiology and Treatment of Lipid Abnormalities in Cerebrotendinous Xanthomatosis: An Integrative Review

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disorder caused by pathogenic variants in CYP27A1, leading to a deficiency in sterol 27-hydroxylase. This defect results in the accumulation of cholestanol and bile alcohols in various tissues, including the brain, tendons and peripheral nerves. We conducted this review to evaluate lipid profile abnormalities in patients with CTX. A search was conducted in PubMed, Embase and the Virtual Health Library in January 2023 to evaluate studies reporting the lipid profiles of CTX patients, including the levels of cholestanol, cholesterol and other lipids. Elevated levels of cholestanol were consistently observed. Most patients presented normal or low serum cholesterol levels. A decrease in chenodeoxycholic acid (CDCA) leads to increased synthesis of cholesterol metabolites, such as bile alcohols 23S-pentol and 25-tetrol 3-glucuronide, which may serve as surrogate follow-up markers in patients with CTX. Lipid abnormalities in CTX have clinical implications. Cholestanol deposition in tissues contributes to clinical manifestations, including neurological symptoms and tendon xanthomas. Dyslipidemia and abnormal cholesterol metabolism may also contribute to the increased risk of atherosclerosis and cardiovascular complications observed in some CTX patients.

Features of the metabolic syndrome and subclinical atherosclerosis in patients with cerebrotendinous xanthomatosis: An augmented risk for premature cardiovascular disease

Background: Cerebrotendinous xanthomatosis (CTX) is a rare lipid storage disease, caused by deficiency of sterol-27-hydroxylase. Xanthomatous lesions in numerous tissues, and an elevation of cholestanol levels, characterize the disease. Its natural course is progressive neurologic deterioration, leading to premature death. Chronic treatment with oral chenodeoxycholic acid (CDCA) reduces cholestanol levels. Occurrence of premature atherosclerosis has been described in CTX in an unknown mechanism.

Aim: The aim of the current work was to evaluate the potential metabolic abnormalities and preclinical vascular changes in Israeli CTX patients.

Methods: Ten subjects with CTX were studied. Features of the metabolic syndrome were evaluated, and carotid intima media thickness (cIMT) was measured in the common carotid arteries.

Results: All patients were diagnosed with CTX, and all received treatment with CDCA, which resulted in normalization of their plasma cholestanol levels. At the conclusion of the follow up, risk factors for CVD and features of MS were present in all the patients and in three patients, cIMT was higher compared to control subjects.

Conclusion: Cardiovascular risk factors and premature vascular changes exist in young CTX patients and proper assessment should be implemented with preventive measures to reduce the risk of atherosclerotic cardiovascular disease in CTX patients.

Rapidly progressive dementia and intractable diarrhea: a teaching case report and a systematic review of cognitive impairment in Whipple’s disease

Objective

Methods

Results

Conclusions

Supplementary Information

Cerebrotendinous Xanthomatosis: Molecular Pathogenesis, Clinical Spectrum, Diagnosis, and Disease-Modifying Treatments

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disorder caused by mutations in the CYP27A1 gene, which encodes the mitochondrial enzyme sterol 27-hydroxylase. Decreased sterol 27-hydroxylase activity results in impaired bile acid synthesis, leading to reduced production of bile acids, especially chenodeoxycholic acid (CDCA), as well as elevated serum cholestanol and urine bile alcohols. The accumulation of cholestanol and cholesterol mainly in the brain, lenses, and tendons results in the characteristic clinical manifestations of CTX. Clinical presentation is characterized by systemic symptoms including neonatal jaundice or cholestasis, refractory diarrhea, juvenile cataracts, tendon xanthomas, osteoporosis, coronary heart disease, and a broad range of neuropsychiatric manifestations. The combinations of symptoms vary from patient to patient and the presenting symptoms, especially in the early disease phase, may be nonspecific, which leads to a substantial diagnostic delay or underdiagnosis. Replacement of CDCA has been approved as a first-line treatment for CTX, and can lead to biochemical and clinical improvements. However, the effect of CDCA treatment is limited once significant neuropsychiatric manifestations are established. The age at diagnosis and initiation of CDCA treatment correlate with the prognosis of patients with CTX. Therefore, early diagnosis and subsequent treatment initiation are essential.

Cardiac Involvement in Movement Disorders

Background

Several conditions represented mainly by movement disorders are associated with cardiac disease, which can be overlooked in clinical practice in the context of a prominent primary neurological disorder.

Objectives

To review neurological conditions that combine movement disorders and primary cardiac involvement.

Methods

A comprehensive and structured literature search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria was conducted to identify disorders combining movement disorders and cardiac disease.

Results

Some movement disorders are commonly or prominently associated with cardiac disease. Neurological and cardiac symptoms may share underlying physiopathological mechanisms in diseases, such as Friedreich's ataxia and Wilson's disease, and in certain metabolic disorders, including Refsum disease, Gaucher disease, a congenital disorder of glycosylation, or cerebrotendinous xanthomatosis. In certain conditions, such as Sydenham's chorea or dilated cardiomyopathy with ataxia syndrome (ATX-DNAJC19), heart involvement can present early in the course of disease, whereas in others such as Friedreich's ataxia or Refsum disease, cardiac symptoms tend to present in later stages. In another 68 acquired or inherited conditions, cardiac involvement or movement disorders are seldom reported.

Conclusions

As cardiac disease is part of the phenotypic spectrum of several movement disorders, heart involvement should be carefully investigated and increased awareness of this association encouraged as it may represent a leading cause of morbidity and mortality.

Chinese patient with cerebrotendinous xanthomatosis confirmed by genetic testing: A case report and literature review

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a treatable autosomal recessive inherited metabolic disorder. It results from a deficiency of sterol 27-hydroxylase (CYP27A1), which is a mitochondrial cytochrome P450 enzyme that catalyzes the hydroxylation of cholesterol and modulates cholesterol homeostasis. Patients with CYP27A1 deficiency show symptoms related to excessive accumulation of cholesterol and cholestanol in lipophilic tissues such as the brain, eyes, tendons, and vessels, resulting in juvenile cataracts, tendon xanthoma, chronic diarrhea, cognitive impairment, ataxia, spastic paraplegia, and peripheral neuropathy. CTX is underdiagnosed as knowledge of the disorder is mainly based on case reports.

CASE SUMMARY

A Chinese family with CTX consisting of one patient and four heterozygous carriers was studied. The patient is a 47-year-old male, who mainly had psychiatric signs but without some cardinal features of CTX such as cataracts, cerebellar ataxia, pyramidal signs and chronic diarrhea. There was a significant increase in the concentration of free fatty acid compared to normal range. Doppler ultrasound of the urinary system showed multiple left kidney stones, a right kidney cyst, and a hypoechoic area in the bladder, which could move with body position. Sagittal and axial magnetic resonance imaging (MRI) of the right ankle joint showed apparent enlargement of the right Achilles tendon and upper medial malleolus flexor tendon, abnormal thickening of the plantar fat, and a small amount of exudation around the fascia in front of the Achilles tendon. Cerebral MRI suggested white matter (WM) demyelination and slight cerebral atrophy. The diagnosis was confirmed by targeted sequencing, which identified compound heterozygous mutations in exon 2 and intron 7 of the CYP27A1 gene (c.435G>T, c.1263+1G>A). Treatment for 3 wk with a combination of lipid-lowering and antipsychotic therapy improved his psychiatric symptoms and normalized the levels of serum free fatty acid. Sediments in the bladder disappeared after therapy.

CONCLUSION

CYP27A1 genetic analysis should be the definitive method for CTX diagnosis. This case suggests that urinary system diseases may be neglected in CTX patients. The clinical, biological, radiological, and genetic characteristics of CTX are summarized to promote early diagnosis and treatment of this disease.

Natural history of neurological abnormalities in cerebrotendinous xanthomatosis

OBJECTIVES

Cerebrotendinous xanthomatosis (CTX) is a rare inherited neurodegenerative disorder in bile acid synthesis. The natural history of neurological abnormalities in CTX is not well understood. The object of this study was to determine neurological progression in CTX.

METHODS

A literature search on PubMed for "cerebrotendinous xanthomatosis" yielded 91 publications that reported cases of CTX patients. Two independent reviewers abstracted information about the presence and age of onset of neurological abnormalities in published CTX cases. For each neurological abnormality, we estimated the probability of its onset at any given age using cumulative incidence function analysis. We also present our own case series, in which five CTX patients were evaluated.

RESULTS

The literature search yielded 194 CTX cases (ages ranging from newborn to 67 years old). The most common neurological abnormalities were corticospinal tract abnormalities including weakness, hyperreflexia, spasticity, Babinski sign (59.8%), ataxia (58.8%), cognitive decline (46.4%), and gait difficulty (38.1%); 68 (35.0%) had baseline cognitive problems. Cumulative incidence function analysis revealed that ataxia, gait difficulties, and corticospinal tract abnormalities developed throughout life, while cognitive decline tended to develop later in life. Of the less common neurological abnormalities, seizures, psychiatric changes and speech changes developed throughout life, while parkinsonism and sensory changes tended to develop later in life. Our case series corroborated this temporal pattern of neurological abnormalities.

CONCLUSION

We provide estimates for the neurological progression of CTX, categorizing neurological abnormalities according to time and probability of development. Our approach may be applicable to other rare disorders.

Epidemiology, diagnosis, and treatment of cerebrotendinous xanthomatosis (CTX)

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder of bile acid synthesis caused by mutations in the cytochrome P450 CYP27A1 gene that result in production of a defective sterol 27-hydroxylase enzyme. CTX is associated with abnormally high levels of cholestanol in the blood and accumulation of cholestanol and cholesterol in the brain, tendon xanthomas, and bile. Hallmark clinical manifestations of CTX include chronic diarrhea, bilateral cataracts, tendon xanthomas, and neurologic dysfunction. Although CTX is a rare disorder, it is thought to be underdiagnosed, as presenting signs and symptoms may be nonspecific with significant overlap with other more common conditions. There is marked variability in signs and symptoms, severity, and age of onset between patients. The disease course is progressive and potentially debilitating or fatal, particularly with respect to neurologic presentations that can include intellectual disability, autism, behavioral and psychiatric problems, and dementia, among others. Treatment with chenodeoxycholic acid (CDCA; chenodiol) is the current standard of care. CDCA can help restore normal sterol, bile acid, bile alcohol, and cholestanol levels. CDCA also appears to be generally effective in preventing adverse clinical manifestations of the disease from occurring or progressing if administered early enough. Improved screening and awareness of the condition may help facilitate early diagnosis and treatment.

Revised consensus statement on the preventive and symptomatic care of patients with leukodystrophies

Leukodystrophies are a broad class of genetic disorders that result in disruption or destruction of central myelination. Although the mechanisms underlying these disorders are heterogeneous, there are many common symptoms that affect patients irrespective of the genetic diagnosis. The comfort and quality of life of these children is a primary goal that can complement efforts directed at curative therapies. Contained within this report is a systems-based approach to management of complications that result from leukodystrophies. We discuss the initial evaluation, identification of common medical issues, and management options to establish a comprehensive, standardized care approach. We will also address clinical topics relevant to select leukodystrophies, such as gallbladder pathology and adrenal insufficiency. The recommendations within this review rely on existing studies and consensus opinions and underscore the need for future research on evidence-based outcomes to better treat the manifestations of this unique set of genetic disorders.

Pathophysiology of cerebrotendinous xanthomatosis

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal-recessive lipid storage disease caused by mutations in the CYP27A1 gene, which lead to deficiency of the mitochondrial enzyme, sterol 27-hydroxylase, resulting in the accumulation of cholestanol in the serum and many affected lesions. To date, more than 50 different CYP27A1 mutations, including missense mutations, frameshifts, and splice site mutations, have been reported worldwide in patients with CTX. Clinical presentation is characterized by neonatal jaundice or cholestasis, refractory diarrhea, juvenile cataracts, tendon xanthomas, osteoporosis, coronary heart disease, and progressive neuropsychiatric disturbances; however, combinations of symptoms vary from patient to patient. Neuropsychiatric abnormalities include mental retardation or dementia, psychiatric symptoms, cerebellar signs, pyramidal signs, progressive myelopathy, peripheral neuropathy, extrapyramidal manifestations, and seizures. Replacement treatment with chenodeoxycholic acid in the early stage of the disease has been reported to improve or even prevent clinical symptoms of CTX. After significant neurological pathology is established, the effect of the treatment is limited and the deterioration of clinical manifestations may continue; therefore, early diagnosis of CTX is crucial.

Mitochondrial function and regulation of macrophage sterol metabolism and inflammatory responses

The aim of this review is to explore the role of mitochondria in regulating macrophage sterol homeostasis and inflammatory responses within the aetiology of atherosclerosis. Macrophage generation of oxysterol activators of liver X receptors (LXRs), via sterol 27-hydroxylase, is regulated by the rate of flux of cholesterol to the inner mitochondrial membrane, via a complex of cholesterol trafficking proteins. Oxysterols are key signalling molecules, regulating the transcriptional activity of LXRs which coordinate macrophage sterol metabolism and cytokine production, key features influencing the impact of these cells within atherosclerotic lesions. The precise identity of the complex of proteins mediating mitochondrial cholesterol trafficking in macrophages remains a matter of debate, but may include steroidogenic acute regulatory protein and translocator protein. There is clear evidence that targeting either of these proteins enhances removal of cholesterol via LXRα-dependent induction of ATP binding cassette transporters (ABCA1, ABCG1) and limits the production of inflammatory cytokines; interventions which influence mitochondrial structure and bioenergetics also impact on removal of cholesterol from macrophages. Thus, molecules which can sustain or improve mitochondrial structure, the function of the electron transport chain, or increase the activity of components of the protein complex involved in cholesterol transfer, may therefore have utility in limiting or regressing atheroma development, reducing the incidence of coronary heart disease and myocardial infarction.

Mitochondrial (dys)function and regulation of macrophage cholesterol efflux

Cholesterol trafficking from the outer to the cholesterol-poor inner mitochondrial membrane requires energized, polarized and actively respiring mitochondria, mediated by a highly regulated multimeric (140-200 kDa) protein complex comprising StAR (steroidogenic acute regulatory protein), mitochondrial TSPO (translocator protein), VDAC (voltage-dependent anion channel), ANT (adenine nucleotide transporter) and associated regulatory proteins. Mitochondrial cholesterol transport is rate-limiting in the CYP27A1 (sterol 27-hydroxylase)-dependent generation of oxysterol ligands for LXR (liver X receptor) transcription factors that regulate the expression of genes encoding proteins in the cholesterol efflux pathway, such as ABC transporters (ATP-binding cassette transporters) ABCA1 and ABCG1. These transporters transfer cholesterol and/or phospholipids across the plasma membrane to (apo)lipoprotein acceptors, generating nascent HDLs (high-density lipoproteins), which can safely transport excess cholesterol through the bloodstream to the liver for excretion in bile. Utilizing information from steroidogenic tissues, we propose that perturbations in mitochondrial function may reduce the efficiency of the cholesterol efflux pathway, favouring accumulation of cholesteryl ester 'foam cells' and allowing the toxic accumulation of free cholesterol at the interface between the endoplasmic reticulum and the mitochondrial membrane. In turn, this will trigger opening of the permeability transition pore, allowing unregulated production of oxysterols via CYP27A1, allowing the accumulation of esterified forms of this oxysterol within human atherosclerotic lesions. Defective cholesterol efflux also induces endoplasmic reticulum stress, proteasomal degradation of ABCA1 and Fas-dependent apoptosis, replicating findings in macrophages in advanced atherosclerotic lesions. Small molecules targeted to mitochondria, capable of sustaining mitochondrial function or improving cholesterol trafficking may aid cholesterol efflux from macrophage 'foam' cells, regressing and stabilizing the atherosclerotic plaque.

Inherited metabolic disorders and cerebral infarction

The association of genetic factors and cerebral infarction (CI) has long been established. A positive family history alone is a recognized risk factor for CI and vascular events in general. However, there are certain inherited conditions that further increase the risk of stroke. These conditions are generally metabolic and mitochondrial genetic defects that have variable modes of inheritance. This article reviews major inherited metabolic disorders that predispose an individual to CI. Ten main conditions will be discussed: Fabry's disease, cerebrotendinous xanthomatosis, tangier disease, familial hypercholesterolemia, homocystinuria, methylmalonic acidemia, glutaric aciduria type I, propionic acidemia, ornithine transcarbamylase deficiency and mitochondrial encephalopathy, lactic acidosis and stroke-like phenomenon.

Cerebrotendinous xanthomatosis: a critical update

Cerebrotendinous xanthomatosis (CTX) also known as van Bogaert–Scherer–Epstein syndrome, Thiebaut’s syndrome and cerebrotendinous cholesterosis, is an autosomal-recessive lipid-storage disease characterized by the triad of juvenile cataracts, tendon xanthomas and progressive neurodegeneration. Excess cholesterol and cholestanol are deposited in multiple organs, including the cerebrum, cerebellum, lens and tendons. Approximately 300 cases are reported worldwide, but it is suspected that the incidence of CTX is underestimated. The disease is attributed to approximately 50 mutations in the CYP27A1 gene coding for the enzyme sterol 27-hydoxylase, which is responsible for initial oxidation of the side chain of the cholesterol molecule in bile acid biosynthesis. CTX has varied clinical presentations, but no genotype–phenotype relationship has been documented. In some intrafamilial cases, clinical presentations may vary considerably. MRI for CTX is sensitive for diagnosis and classically demonstrates cerebral and cerebellar atrophy and xanthomatous lesions preferentially affecting the dentate nuclei. Patients have high serum levels of cholestanol with normal total cholesterol and increased urinary excretion of bile acids. Treatment of patients with chenodeoxycholic acid, particularly when used along with HMG-CoA reductase inhibitors (statins) or low-density lipoprotein apheresis, can normalize cholestanol levels as well as prevent further degeneration. Therefore, the need for early diagnosis is well documented in the literature, as it prevents the significant morbidity and mortality associated with this disease.