Diagnosis, treatment, and clinical outcomes in 43 cases with cerebrotendinous xanthomatosis

Spectrum of Inherited Childhood-Onset Dystonia: Case Series of 19 Families With Genotype and Phenotype Characterization Highlighting the Treatable Causes

Childhood-onset dystonia, a clinically and genetically diverse group of disorders, can be challenging to diagnose. Information on the genotype and phenotype spectrum in the Indian population is limited. This study reports the clinical and molecular findings of monogenic childhood-onset dystonia in 22 individuals from 19 Indian families. Complex dystonia was the most frequent type, followed by combined and isolated forms. A total of 23 variants across 17 genes were identified, including nine novel ones. These disorders include four autosomal dominant, one X-linked recessive, one mitochondrial, and the remaining 11 autosomal recessive conditions. Five potentially treatable disorders were identified, and treatment was initiated in three families, showing satisfactory responses, particularly in dopa-responsive dystonias. Our study contributes four additional genes-CYP27A1, NDUFAF3, FUCA1, and FIG4-to the list of genes associated with complex dystonia. Exome sequencing proved crucial in diagnosing the etiology of dystonia, identifying treatable forms, and aiding genetic counseling. This study emphasizes the significance of using NGS for early genetic diagnosis to enable timely targeted therapies, offer precise genetic counseling to families, and prevent recurrence in the family.

Efficacy, safety, and tolerability of chenodeoxycholic acid (CDCA) in adult patients with cerebrotendinous xanthomatosis (RESTORE): A randomized withdrawal, double-blind, placebo-controlled, crossover phase-3 study

PURPOSE

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by pathogenic variants in CYP27A1, resulting in sterol 27-hydroxylase deficiency and accumulation of cholestanol and bile alcohols. Clinical features include cholestasis, diarrhea, cataracts, tendon xanthomas, and neurological deterioration. Chenodeoxycholic acid (CDCA) is the standard treatment for CTX. The effects of CDCA withdrawal on CTX biomarkers and safety in adult patients were evaluated.

METHODS

Patients (≥16 years) received CDCA 750-mg/day for 2 8-week open-label periods followed by double-blinded (DB) CDCA or placebo for 2 4-week periods. Key endpoints included changes from baseline in CTX biomarkers (23S-pentol, cholestanol, 7αC4, 7α12αC4) and the proportion of patients requiring CDCA rescue during DB periods.

RESULTS

CDCA withdrawal resulted in a 20-fold increase in 23S-pentol and increases in cholestanol (2.8-fold), 7αC4 (50-fold), and 7α12αC4 (14-fold). During the DB withdrawal periods, 61% of participants on placebo required rescue medication. CDCA treatment was well tolerated; the most common treatment-emergent adverse events were diarrhea and headache, most of them mild/moderate in severity and not considered treatment related.

CONCLUSION

CDCA withdrawal caused statistically significant increases in CTX biomarkers and necessitated rescue therapy in most participants. CDCA treatment is critical for control of biochemical abnormalities and helps avoid disease progression.

Autosomal Recessive Ataxias in Northeast Brazil: A Regional Multicenter Case Series

Hereditary cerebellar ataxias are a diverse group of neurodegenerative disorders characterized by progressive cerebellar dysfunction and possible multisystemic involvement. While significant advancements have been made in understanding autosomal dominant cerebellar ataxias (ADCAs), autosomal recessive cerebellar ataxias (ARCAs) remain less extensively investigated than autosomal dominant ataxias, particularly in regions with high consanguinity. This study aimed to characterize 57 patients with ARCAs in Ceará, northeast Brazil. We analyzed 57 patients diagnosed with ARCAs caused by biallelic variants in ARCA-associated genes. Patients underwent clinical evaluations, including neurological examinations and functional assessments.

RESULTS

Friedreich's ataxia (FRDA) was the most prevalent diagnosis, accounting for 12 cases (21%), followed by Ataxia-Telangiectasia (A-T) with (N = 9; 15.8%) and Niemann-Pick Disease Type C (NPC) (N = 9; 15.8%). Metabolic disorders, including Cerebrotendinous Xanthomatosis (N = 6;10.5%) were also common causes. The cohort demonstrated a broad age distribution, with childhood-onset conditions such as A-T predominantly affecting younger patients. In contrast, adult-onset conditions like FRDA and NPC were more common in those aged 18 years and older.

DISCUSSION

This study highlights the heterogeneity of ARCAs in a region with high consanguinity, reflecting these disorders' diverse genetic and clinical spectrum.

CONCLUSION

The clinical and genetic characterization of ARCAs presented in this case series emphasizes the importance of early diagnosis, genetic confirmation, and targeted management strategies. Our findings highlight the need for continued research and expanded diagnostic programs, particularly in regions with high consanguinity, to improve patient outcomes and advance therapeutic development.

Early diagnosis and follow-up of cerebrotendinous xanthomatosis in infant siblings presenting with congenital diarrhea: A case study from Saudi Arabia

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive neurometabolic genetic disease resulting from defects in the bile acid metabolism. This report describes cases diagnosed with CTX at an exceptionally early age - 4 months (Patient #2 and #3) - making them the youngest reported cases to date. All three presented with intractable congenital diarrhea, a hallmark manifestation of the disease. The diagnosis was confirmed through metabolic bile acids analysis in urine and genetic testing. The siblings were treated with Chenodeoxycholic acid (15 mg/kg/day) during the first year of treatment, resulting in an improvement in diarrhea in all three. However, cognitive function remained unimproved in one patient. Additionally, the presence of dysmorphic features, observed in these patients, have not been documented in previous CTX cases. The diagnosis prompted solely by the persistent diarrhea, highlights a critical, under-recognized early manifestation. These findings underscore the importance of raising awareness among physicians to enable early diagnosis and timely treatment, which may prevent disease progression.

Case report: Cerebrotendinous Xanthomatosis masquerading as adult ADHD in psychiatric practice

Introduction

This case report details the presentation of a patient who initially sought consultation at a psychiatric outpatient clinic with symptoms suggestive of Attention-Deficit/Hyperactivity Disorder (ADHD); however, further evaluation revealed a diagnosis of Cerebrotendinous Xanthomatosis (CTX). CTX, a genetic disorder impacting lipid metabolism, is often overlooked in differential diagnoses due to its rarity. This case underscores the importance of considering alternative diagnoses in adults exhibiting ADHD-like symptoms without a childhood history of the disorder, adding to the literature on diagnostic complexities in psychiatric practice.

Case presentation

A 33-year-old man visited a psychiatric outpatient clinic with symptoms such as increasing distractibility and inattention, requesting an evaluation for adult ADHD. However, the absence of an ADHD history in childhood, coupled with progressive neurological symptoms and tendon xanthomas, led to further investigation. Comprehensive neurological assessments, including neuroimaging and genetic testing, ultimately diagnosed him with CTX. Treatment with chenodeoxycholic acid (CDCA) resulted in stabilization of cognitive function, although improvement in gait disturbances and tremors remained minimal.

Conclusion

This case demonstrates that CTX can masquerade as adult ADHD, emphasizing the necessity for thorough assessments in atypical ADHD presentations. Psychiatrists should consider rare metabolic disorders like CTX in similar cases, which may enable timely intervention and improve patient outcomes.

A sterol panel for rare lipid disorders: sitosterolemia, cerebrotendinous xanthomatosis and Smith-Lemli-Opitz syndrome

Disease-specific sterols accumulate in the blood of patients with several rare lipid disorders. Biochemical measurement of these sterols is important for correct diagnosis and sometimes monitoring of treatment. Existing methods to measure sterols in blood, particularly plant sterols, are often laborious and time consuming. Partly as a result, clinical access to sterol measurements is limited in many parts of the world. A simple and rapid method to extract free sterols from human serum and quantitate their concentration using isotope-dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) without derivatization was developed. The method was designed to be compatible with routine workflows (e.g., 96-well format) in a clinical lab and extensively validated. Serum from at least 125 controls were analyzed and used to estimate the upper reference limits for sitosterol, campesterol, stigmasterol, desmosterol, 7-dehydrocholesterol (7DHC), lathosterol, and cholestanol. Serum from patients with the rare lipid disorders sitosterolemia (n = 7), Smith-Lemli-Opitz syndrome (SLOS; n = 1), and cerebrotendinous xanthomatosis (CTX; n = 1) were analyzed. All seven sitosterolemia patients had greatly elevated levels of free plant sterols (sitosterol, campesterol, and stigmasterol) compared to the controls. The SLOS serum contained massively increased concentrations of 7DHC. CTX serum contained greatly increased concentrations of cholestanol, as well as 7DHC and lathosterol. Spiking experiments indicated that the method is likely also useful for the diagnosis of desmosterolosis and lathosterolosis. The reported method is a relatively simple and fast LC-MS/MS method capable of quantitating diagnostically important sterols and differentiated patients with three rare lipid disorders from controls.

Cerebrotendinous xanthomatosis: A complex interplay between a clinically and genetically heterogeneous condition

BACKGROUND AND PURPOSE

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid storage disease characterized by abnormal bile acid synthesis. It often presents with systemic and neurological manifestations; however, atypical presentations can lead to significant diagnostic challenges. This case report highlights the diagnostic complexities and management considerations in a patient with an uncommon presentation of CTX.

METHODS

We present a patient with a 25-year history of spastic paraparesis, initially suggestive of hereditary spastic paraplegia (HSP), ultimately diagnosed with CTX associated with a novel CYP27A1 variant of uncertain significance (VUS).

RESULTS

A 53-year-old Greek woman presented with a 25-year history of slowly progressive spastic paraparesis. Initial investigations were largely unremarkable, leading to a presumptive diagnosis of a hereditary spastic paraplegia (HSP)-like syndrome. After 5 years of slow disease progression, the patient developed right ankle swelling. MRI revealed significant enlargement of the Achilles tendon, suggestive of xanthoma infiltration. Subsequent genetic testing identified a homozygous variant of uncertain significance (VUS) in the CYP27A1 gene. Biochemical analyses revealed elevated cholestanol levels and cholestanepentol glucuronide in urine, confirming the diagnosis of CTX. Treatment with chenodeoxycholic acid stabilized her condition over 3 years, but advanced disease limited efficacy in improving disability.

CONCLUSION

This case highlights the diagnostic challenges associated with CTX, stemming from its relative rarity and significant clinical heterogeneity. It emphasizes the importance of a comprehensive approach combining clinical suspicion, imaging, genetic testing and biochemical analyses for accurate diagnosis, interpretation of VUS and management of rare conditions like CTX.

Clinicogenetic characterization of cerebrotendinous xanthomatosis in Brazil

There are few cerebrotendineous xanthomatosis (CTX) case series and observational studies including a significant number of Latin American patients. We describe a multicenter Brazilian cohort of patients with CTX highlighting their clinical phenotype, recurrent variants and assessing possible genotype-phenotype correlations. We analyzed data from all patients with clinical and molecular or biochemical diagnosis of CTX regularly followed at six genetics reference centers in Brazil between March 2020 and August 2023. We evaluated 38 CTX patients from 26 families, originating from 4 different geographical regions in Brazil. Genetic analysis identified 13 variants in the CYP27A1 gene within our population, including 3 variants that had not been previously described. The most frequent initial symptom of CTX in Brazil was cataract (27%), followed by xanthomas (24%), chronic diarrhea (13.5%), and developmental delay (13.5%). We observed that the median age at loss of ambulation correlates with the age of onset of neurological symptoms, with an average interval of 10 years (interquartile range 6.9 to 11 years). This study represents the largest CTX case series ever reported in South America. We describe phenotypic characteristics and report three new pathogenic or likely pathogenic variants.

Polyneuropathy in Cerebrotendinous Xanthomatosis: Diagnostic Challenges and Potential for Therapeutic Intervention

Cerebrotendinous xanthomatosis (CTX) is a rare metabolic disorder caused by mutations in the CYP27A1 gene, leading to cholestanol accumulation in various tissues, including peripheral nerves. Polyneuropathy is an underrecognized feature with considerable variability in clinical presentation and neurophysiological findings in CTX. This review assesses the prevalence, clinical manifestations, and diagnostic methodologies of polyneuropathy in CTX, exploring its underlying mechanisms and potential treatment outcomes. A literature review was conducted using PubMed, Embase, and the Virtual Health Library databases with search terms related to CTX and polyneuropathy. A total of 892 articles were initially identified, with 59 selected for in-depth analysis. The review focused on studies examining peripheral nerve involvement in CTX, including nerve conduction studies, electromyography, and nerve ultrasound. Polyneuropathy in CTX was observed in 50% to 77.7% of patients across multiple case series. Neurophysiological findings varied, with reports of axonal, demyelinating, and mixed polyneuropathies. Clinical presentation included lower limb atrophy, pes cavus, and distal weakness, with sensory symptoms less frequently reported. Treatment with chenodeoxycholic acid (CDCA) showed potential in improving nerve conduction parameters, although the response was variable and dependent on the timing of intervention. Polyneuropathy in CTX presents significant diagnostic challenges due to its heterogeneous presentation and varying neurophysiological findings. Early recognition and intervention are crucial for improving patient outcomes. Peripheral nerve ultrasound is a promising diagnostic tool, complementing traditional neurophysiological assessments. Further research is needed to standardize protocols and explore the full therapeutic potential of CDCA in managing CTX-related polyneuropathy.

The clinical and demographic characteristics of patients with late-diagnosed cerebrotendinous xanthomatosis in a Turkish population

AIM

The aim of this study was to examine the clinical, laboratory and demographic characteristics of patients diagnosed with cerebrotendinous xanthomatosis (CTX).

MATERIALS AND METHODS

This study included 11 patients followed up in the Pediatric Metabolism Polyclinic for a diagnosis of CTX. The diagnosis of CTX was made from high blood cholestanol level and CYP27A1 gene analysis. All the cases diagnosed with CTX for whom clinical and laboratory findings were evaluated were included in the study.

RESULTS

Evaluation was made of 11 patients from five different families. The diagnosis was established 25 years after symptoms first appeared. The diagnosis was made because of bilateral cataracts in two patients, tendon xanthomas in two, and as a result of family screening in seven. Tendon xanthomas were present in 36.3% of the patients, and there was a history of cataract in 54.5%. In the current study, mental retardation was determined in 72% of the patients, psychiatric findings in 36%, epilepsy in 36%, pyramidal-extrapyramidal findings in 45%, and postural tremor in 54%. In addition, neuropsychiatric symptoms were seen at different rates in patients with different gene alleles. No tendon xanthomas were determined in the cases with c.1263 + 4A>T and c.808C>T mutations. Cataract was determined in all the cases with homozygote c.1263 + 4A>T mutation.

CONCLUSION

In this study, it was determined that the cases were diagnosed late despite the onset of symptoms providing clues for diagnosis at an early age. It was determined that the delay in diagnosis was 25 years.

The importance of synthetic pharmacotherapy for recessive cerebellar ataxias

INTRODUCTION

The last decade has witnessed major breakthroughs in identifying novel genetic causes of hereditary ataxias, deepening our understanding of disease mechanisms, and developing therapies for these debilitating disorders.

AREAS COVERED

This article reviews the currently approved and most promising candidate pharmacotherapies in relation to the known disease mechanisms of the most prevalent autosomal recessive ataxias. Omaveloxolone is an Nrf2 activator that increases antioxidant defense and was recently approved for treatment of Friedreich ataxia. Its therapeutic effect is modest, and further research is needed to find synergistic treatments that would halt or reverse disease progression. Promising approaches include upregulation of frataxin expression by epigenetic mechanisms, direct protein replacement, and gene replacement therapy. For ataxia-telangiectasia, promising approaches include splice-switching antisense oligonucleotides and small molecules targeting oxidative stress, inflammation, and mitochondrial function. Rare recessive ataxias for which disease-modifying therapies exist are also reviewed, emphasizing recently approved therapies. Evidence supporting the use of riluzole and acetyl-leucine in recessive ataxias is discussed.

EXPERT OPINION

Advances in genetic therapies for other neurogenetic conditions have paved the way to implement feasible approaches with potential dramatic benefits. Particularly, as we develop effective treatments for these conditions, we may need to combine therapies, consider newborn testing for pre-symptomatic treatment, and optimize non-pharmacological approaches.

Cognitive impairment in children and adults with cerebrotendinous xanthomatosis: A French cohort study

Cerebrotendinous xanthomatosis is a rare and treatable metabolic disorder related to the accumulation of cholestanol. This disorder is primarily associated with motor and cognitive impairments, although the latter has not been extensively characterized. The objectives of this work were to define the cognitive profile found in cerebrotendinous xanthomatosis patients, investigate the progression of cognitive impairment over time, and search for radio-clinical correlations. Through a multicentric chart review study, we collected cognitive and radiological data from nine children and eighteen adults with genetically proven cerebrotendinous xanthomatosis. We performed a volumetric and morphological analysis of the brain magnetic resonance imaging. In our cohort, 44% (4/9) of children and 78% (14/18) of adults exhibited cognitive impairment that can be severe. The study revealed a significant impairment in various cognitive domains, specifically executive, attentional, language, and visuo-spatial. Among adults, 16% (3/18) developed dementia after age 50. These three patients had delayed chenodeoxycholic acid treatment and important cerebral atrophy. Besides these three cases of late-onset cognitive decline, Mini-Mental State Evaluation was generally stable, suggesting cognitive impairment due to a neurodevelopmental disorder and persisting in adulthood. Cognitive impairment was less common in children, possibly related to early chenodeoxycholic acid treatment in our cohort. The severity of magnetic resonance imaging abnormalities did not predict cognitive impairment in patients. Overall, in cerebrotendinous xanthomatosis, cognitive impairment can be severe and mainly neurodevelopmental. Early chenodeoxycholic acid treatment might be associated with a reduced risk of cognitive decline.

Rare genetic cerebrotendinous xanthomatosis (CTX) cases without cholestanol elevation but with prominent cholesterol-rich tendon xanthomas

Cerebrotendinous xanthomatosis (CTX) is a rare inherited metabolic disease attributed to the mutation of the gene CYP27A1, resulting in sterol 27-hydroxylase deficiency characterized by deposition of cholestanol and cholesterol in several tissues, like the central nervous system and tendons. Furthermore, cataracts, gallstones, diarrhea and premature atherosclerosis have been reported. Nonetheless, clinical development is extremely heterogeneous in CTX. We report here two cases of CTX genetic alteration in the absence of cholestanol elevation in plasma and tendons but with prominent xanthomas. We propose that CTX may not be characteized by increased plasma cholestanol concentration due to alteration in the sterol 27-hydroxylase gene, but is a more complex pathology where there is significant genetic heterogeneity caused by various CYP27A1 mutations.

Case report: Cerebrotendinous xanthomatosis treatment follow-up

Xanthomatosis is a genetic disease inherited in an autosomal recessive manner. The specific phenotypic features are associated with patient's genetic profile. The result of the mutation is disorder of cholesterol synthesis and the accumulation of its precursors in tissues. The characteristic symptoms are progressive cerebellar ataxia, cataract, diarrhea, and the deposition of cholesterol in the tendons. Our objective is to follow-up information to treatment efficacy of 22-year-old patient diagnosed with cerebrotendinous xanthomatosis through 1.5 year observation. In 2012, an 11-year-old patient with a long history of deformed feet and frequent yellowing of the skin, was admitted to the Department of Neurology due to seizures. In 2013, the patient began to suffer from diarrhea, and its frequency was correlated with the concentration of bilirubin in the blood. In the same year cataract was diagnosed. Gradually, the patient starts to complain about progressive difficulties in moving. In 2019, genetic tests confirmed the diagnosis of cerebrotendinous xanthomatosis. Since July 2021, the patient has been treated with chenodeoxycholic acid. The deterioration of patient's mobility has been significantly inhibited, consequently his quality of life has improved. The presented case report underscores the efficacy of CDCA supplementation in halting the progression of CTX, resulting in marked improvements in the patient's quality of life.

Clinical, biochemical, and molecular insights into Cerebrotendinous Xanthomatosis: A nationwide study of 100 Turkish individuals

OBJECTIVE

Cerebrotendinous xanthomatosis (CTX) is an inherited metabolic disorder characterized by progressive neurologic and extraneurologic findings. The aim of this retrospective, descriptive study was to explore the time of presentation and diagnosis, and to expand the phenotype and genotype of CTX, based on a nationwide and comprehensive series of patients in Turkey.

METHODS

The demographic, clinical, biochemical and genotypic characteristics of the CTX patients were reviewed. Data on molecular analysis, age of onset and diagnosis, diagnostic delay, neurologic and extraneurologic symptomatology, results of plasma cholestanol levels, brain magnetic resonance imaging and electromyography at the time of diagnosis were reviewed.

RESULTS

100 confirmed CTX patients from 72 families were included. The mean age at diagnosis was 28.16 ± 14.28 years, and diagnostic delay was 18.39 ± 13.71 years. 36 patients were diagnosed in childhood. Frequency of intention tremor (p = 0.069), peripheral neuropathy (p = 0.234) and psychiatric manifestations (p = 0.396) did not differ between two groups, demonstrating the high rate in pediatric patients. Three adult patients showed a milder phenotype without neurologic involvement. Seven patients had normal plasma cholestanol levels despite neurological impairment. Sequencing of the CYP27A1 gene revealed 25 different variants, with a novel c.671_672del variant not previously described in literature.

CONCLUSION

Based on the observations of this Turkish CTX cohort, it is emphasized that the true prevalence of CTX is probably underestimated and that it has a wide spectrum of clinical phenotypes even without neurological impairment. In children, abnormal cerebellar findings, peripheral neuropathy and psychiatric findings associated with intellectual disability have been suggested as warning signs to avoid diagnostic delay. In cases of clinical suspicion, molecular analysis is recommended despite normal plasma cholestanol levels, as severe neurologic involvement may occur in CTX patients without elevated cholestanol levels.

Chenodeoxycholic acid (CDCA) treatment during pregnancy in women with cerebrotendinous xanthomatosis (CTX): Lessons learned from 19 pregnancies

PURPOSE

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive bile acid synthesis disorder. Biallelic pathogenic variants in CYP27A1, encoding for sterol 27-hydroxylase, impair cholic acid (CA) and chenodeoxycholic acid (CDCA) synthesis and lead to accumulation of cholestanol and C27 bile alcohols. Treatment with CDCA decreases the accumulation of these harmful metabolites and slows disease progression. Currently, CDCA is contraindicated for use during pregnancy based on animal studies that showed that high-dose CDCA may cause fetal harm when administered to pregnant animals. Data regarding the safety of CDCA treatment in humans are lacking.

METHODS

We present a case series of 19 pregnancies in 9 women with CTX who either received CDCA treatment throughout pregnancy or did not.

RESULTS

In 11 pregnancies where mothers continued CDCA treatment, no complications were reported, and newborns were born at or near full term, with normal birth weight and Apgar scores. In 8 pregnancies where mothers did not receive CDCA, 2 newborns experienced elevated bilirubin soon after birth. One woman who stopped treatment during her pregnancy deteriorated neurologically while off treatment.

CONCLUSION

The data we present support the benefit of continued CDCA treatment in pregnant women with CTX for both the affected women and their offspring.

Genetically and clinically confirmed atypical cerebrotendinous xanthomatosis with normal cholestanol and marked elevations of bile acid precursors and bile alcohols

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid disorder. Affected patients often remain undiagnosed until the age of 20-30 years, when they have already developed significant neurologic disease that may not be reversible. An elevated plasma cholestanol concentration has been accepted as a diagnostic criterion for CTX for decades.

OBJECTIVE

Full biochemical characterization was performed for three genetically and clinically confirmed atypical CTX cases with normal plasma cholestanol levels.

METHODS

Clinical assessment and genetic/biochemical testing for patients with CTX was performed by their physician providing routine standard of care.

RESULTS

We report three new atypical CTX cases with large extensor tendon xanthomas but normal plasma cholestanol levels. All three cases had marked elevations of bile acid precursors and bile alcohols in plasma and urine that decreased on treatment with chenodeoxycholic acid. We also review eight published cases of atypical CTX with normal/near normal circulating cholestanol levels.

CONCLUSION

The atypical biochemical presentation of these cases provides a diagnostic challenge for CTX, a disorder for which cholestanol has been believed to be a sensitive biomarker. These cases demonstrate measurements of plasma cholestanol alone are insufficient to exclude a diagnosis of CTX. The data presented is consistent with the concept that bile acid precursors and bile alcohols are sensitive biomarkers for atypical CTX with normal cholestanol, and that such testing is indicated, along with CYP27A1 gene analyses, in patients presenting with significant tendon and/or tuberous xanthomas and/or neurologic disease in early adulthood despite normal or near normal cholesterol and cholestanol levels.

Malar rash and hand tremor in early symptoms of cerebrotendinous xanthomatosis and the effect of chenodeoxycholic acid on them

BACKGROUND

Cerebrotendinous xanthomatosis (CTX, OMIM #213700) is a rare but treatable lipid storage disease resulting from mutations in the CYP27A1 gene.

PURPOSE

The study aims to evaluate patients diagnosed with CTX and reveal new information, especially about the signs of CTX and patients' response to the treatment.

METHODS

The study was conducted retrospectively in 12 definitively diagnosed CTX patients. The patients' clinical, laboratory, imaging, genetic findings, and chenodeoxycholic acid (CDCA) treatment results were analyzed.

RESULTS

The median age at diagnosis for the patients was 16.5 years (minimum-maximum: 7-32). Juvenile cataracts, detected in more than 90% (11/12) of the patients, were the most common clinical finding. Malar rash, not previously reported in the literature for CTX, was present in 75% (9/12) of the patients. Hand tremors, the first neurological symptom, occurred in adolescence and were the initial symptom of the disease in five patients. Hand tremors were present in 83.3% (10/12) of the patients. Hand tremors (in 5 patients) and malar rash (in 2 patients) were clinical findings with full recovery due to the CDCA treatment.

CONCLUSION

The study defines the malar rash finding, which has not been reported in the literature before, as a possible new clinical finding in CTX disease, attributed to its partial or full recovery with CDCA treatment. Additionally, as a novelty in the literature, our study highlights the full recovery of neurological findings, such as hand tremors, in CTX. Patients presenting with hand tremors and malar rash, especially in adolescence, should undergo CTX investigation for early diagnosis and treatment.

Clinical and Imaging Profile of Patients with Cerebrotendinous Xanthomatosis - a Video Case Series from India

Background

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by bi-allelic pathogenic variants in CYP27A1 gene that results in the deposition of cholestanol in the eyes, tendons, soft tissues and nervous system leading to cataracts, xanthomas, and various neuropsychiatric manifestations. The aim of our study is to describe the clinical, radiological and genetic profile of patients with CTX.

Methods

This is a retrospective chart review of patients with CTX diagnosed based on classical clinical and radiological findings. The available clinical details, and investigations, including imaging, electrophysiological, pathological and genetic data, were documented.

Results

Five patients (4 males) were recruited in the study. The median age at presentation was 32 years (range: 21-66 years). Walking difficulty was the most common symptom at presentation. All patients had cataracts, tendon xanthomas, eye movement abnormalities, dysarthria, pyramidal signs, ataxia and gait abnormality. Dystonia was noted in three patients. Palatal tremor and parkinsonism were noted in one patient each. In MRI brain, dentate, and corticospinal tract involvement were the most frequent imaging findings. Bilateral hypertrophic olivary degeneration was noted in one patient and hot cross bun sign in two. Three patients underwent genetic testing and all had pathogenic variants confirming the diagnosis.

Discussion

CTX is a rare treatable disorder. Apart from the usual neurological presentation with spastic-ataxia, it can present at a later age with parkinsonism. Typical patterns of imaging findings are helpful in early diagnosis which aids in the treatment to prevent the neurological sequelae of the disease.

The 20-Year Diagnostic Odyssey of a Milder Form of Cerebrotendinous Xanthomatosis

Tendinous xanthomas are usually a sign of genetic dyslipidemias and are said to be pathognomonic for familial hypercholesterolemia. However, the differential diagnosis must also include rarer forms of genetic dyslipidemias such as cerebrotendinous xanthomatosis (CTX). In this report, we present the diagnostic odyssey of a French-Canadian patient presenting with Achilles tendon xanthomas and an unusual mild to moderate hypercholesterolemia. Comprehensive biochemical and genetic investigations confirmed the diagnosis of CTX, 20 years after the onset of her first symptoms. We also describe a new variant in the CYP27A1 gene associated with this atypical case and expand the clinical phenotype of this rare genetic condition. CTX is thought to be underdiagnosed, and early diagnosis and treatment of this disease is essential as it has been shown to greatly improve the patient's symptoms and prognosis.

Living with Cerebrotendinous Xanthomatosis: Patient, Caregiver, and Expert Perspectives

In this article, patients with cerebrotendinous xanthomatosis (CTX) and caregivers detail their experience with lifelong symptoms, diagnosis, treatment and efficacy, and ongoing disease management. One patient and four caregivers describe the challenges associated with pursuing a correct diagnosis for years before testing confirmed a CTX diagnosis. They also detail their ongoing struggles and desire for greater access to physicians with CTX knowledge and to reliable online resources to continue their education about the disease and strategies for symptom management. The expert perspective is a direct response by three CTX researchers, including physicians who are treating patients with CTX in the United States and experts whose laboratories provide genetic and biochemical testing for CTX. They respond to many of the patient and caregiver concerns, including steps that are being taken to identify CTX earlier and provide access to confirmatory diagnostic testing sooner, and suggest the best online resources for CTX-related information and access to webinars and support groups. While the expert perspective is a direct response to the patient and caregiver authors' CTX journeys, it should be beneficial to any patient with CTX or their caregivers.

Cerebrotendinous Xanthomatosis, a Treatable Disorder Often Missed: Case Series of Three Patients Confirmed by Genetic Testing

ABSTRACT

Cerebrotendinous xanthomatosis (CTX) is a treatable autosomal recessive disorder with varied clinical manifestations and age of onset and is often diagnosed late. We report three cases of CTX who presented at our center with clinical features of frequent diarrhea, early cataracts, xanthomas, cognitive decline, ataxia, neuropathy, and other manifestations of CTX. Magnetic resonance imaging (MRI) brain in all three patients revealed abnormalities consistent with CTX. Diagnosis was confirmed by next-generation sequencing. Chenodeoxycholic acid (CDCA) is recommended as the drug of choice, as it can halt the disease progression and reverse some of the symptoms. In addition to late diagnosis, nonavailability of CDCA in our part of world adds to the problem of management of such patients; therefore, they are often started on alternative therapies, which are less effective.

Characterization of Postprandial Bile Acid Profiles and Glucose Metabolism in Cerebrotendinous Xanthomatosis

Cerebrotendinous xanthomatosis (CTX) is a rare inherited disease characterized by sterol 27-hydroxylase (CYP27A1) deficiency and, thus, a lack of bile acid synthesis with a marked accumulation of 7α-hydroxylated bile acid precursors. In addition to their renowned lipid-emulgating role, bile acids have been shown to stimulate secretion of the glucose-lowering and satiety-promoting gut hormone glucagon-like peptide 1 (GLP-1). In this paper, we examined postprandial bile acid, glucose, insulin, GLP-1 and fibroblast growth factor 19 (FGF19) plasma profiles in patients with CTX and matched healthy controls. Seven patients and seven age, gender and body mass index matched controls were included and subjected to a 4 h mixed meal test with regular blood sampling. CTX patients withdrew from chenodeoxycholic acid (CDCA) and statin therapy three weeks prior to the test. Postprandial levels of total bile acids were significantly lower in CTX patients and consisted of residual CDCA with low amounts of ursodeoxycholic acid (UDCA). The postprandial plasma glucose peak concentration occurred later in CTX patients compared to controls, and patients' insulin levels remained elevated for a longer time. Postprandial GLP-1 levels were slightly higher in CTX subjects whereas postprandial FGF19 levels were lower in CTX subjects. This novel characterization of CTX patients reveals very low circulating bile acid levels and FGF19 levels, aberrant postprandial glucose and insulin profiles, and elevated postprandial GLP-1 responses.

Treatment of cerebrotendinous xanthomatosis in pregnancy: Patient and physician perspectives

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive disorder of bile acid synthesis that presents with varied and progressive symptomology. Early treatment with chenodeoxycholic acid (CDCA) improves symptoms and slows degeneration. Patients with CTX are commonly recommended to discontinue CDCA treatment during pregnancy because of theoretical risks to the fetus, but patient and clinician concerns about the risks of stopping treatment cause uncertainty. Herein, we report the experiences and perspectives of two women with CTX from the time of diagnosis through pregnancy, as well as decisions regarding CDCA treatment during pregnancy. Before becoming pregnant, both women were concerned about potential risks to their newborns if they continued or stopped CDCA treatment during pregnancy. Reassurance from their CTX specialist was the primary factor in their decision to continue treatment during pregnancy. After pregnancies complicated by preeclampsia, one gave birth to a healthy infant and the other gave birth to an infant later diagnosed with periventricular leukomalacia. Neither experienced CDCA-related complications.

Cerebrotendinous xanthomatosis tremor successfully controlled post-ventral intermediate nucleus-deep brain stimulation: a case report

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by a deficiency of the sterol 27-hydroxylase enzyme. This deficiency results in excess production and accumulation of cholestanol, which can lead to many clinical findings within the first three decades of life, including progressive neurological dysfunction. This is a treatable condition with improvements in neurological and non-neurological symptoms upon the early initiation of replacement therapy. This case report details a 42 years-old left-handed male in whom deep brain stimulation (DBS) intervention was pursued due to a limiting tremor related to delayed diagnosis and treatment of CTX at 22 years old. The application of DBS in treating tremors in a CTX patient has not previously been reported. For our patient, application of DBS led to meaningful and longstanding tremor control benefits that have required minimal changes to stimulation parameters post-DBS. These improvements to tremor were achieved without negative impact to his other CTX related comorbidities.

Prevalence of cerebrotendinous xanthomatosis among patients diagnosed with early-onset idiopathic bilateral cataracts: final analysis

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive bile acid synthesis disorder caused by pathologic variants in CYP27A1, a gene involved in bile acid synthesis. Impaired function in this gene leads to accumulation of plasma cholestanol (PC) in various tissues, often in early childhood, resulting in such clinical signs as infantile diarrhea, early-onset bilateral cataracts, and neurological deterioration. The current study aimed to identify cases of CTX in a population of patients with a greater CTX prevalence than the general population, to facilitate early diagnosis. Patients diagnosed with early-onset, apparently idiopathic, bilateral cataracts between the ages of 2 and 21 years were enrolled. Genetic testing of patients with elevated PC and urinary bile alcohol (UBA) levels was used to confirm CTX diagnosis and determine CTX prevalence. Of 426 patients who completed the study, 26 met genetic testing criteria (PC ≥ 0.4 mg/dL and positive UBA test), and 4 were confirmed to have CTX. Prevalence was found to be 0.9% in enrolled patients, and 15.4% in patients who met the criteria for genetic testing.

Serum Lipidomic Screen Identifies Key Metabolites, Pathways, and Disease Classifiers in Crohn's Disease

BACKGROUND

There is an unmet medical need for biomarkers that capture host and environmental contributions in inflammatory bowel diseases (IBDs). This study aimed at testing the potential of circulating lipids as disease classifiers given their major roles in inflammation.

METHODS

We applied a previously validated comprehensive high-resolution liquid chromatography-mass spectrometry-based untargeted lipidomic workflow covering 25 lipid subclasses to serum samples from 100 Crohn's disease (CD) patients and 100 matched control subjects. Findings were replicated and expanded in another 200 CD patients and 200 control subjects. Key metabolites were tested for associations with disease behavior and location, and classification models were built and validated. Their association with disease activity was tested using an independent cohort of 42 CD patients.

RESULTS

We identified >70 metabolites with strong association (P < 1 × 10-4, q < 5 × 10-4) to CD. Highly performing classification models (area under the curve > 0.84-0.97) could be built with as few as 5 to 9 different metabolites, representing 6 major correlated lipid clusters. These classifiers included a phosphatidylethanolamine ether (O-16:0/20:4), a sphingomyelin (d18:1/21:0) and a cholesterol ester (14:1), a very long-chain dicarboxylic acid [28:1(OH)] and sitosterol sulfate. These classifiers and correlated lipids indicate a dysregulated metabolism in host cells, notably in peroxisomes, as well as dysbiosis, oxidative stress, compromised inflammation resolution, or intestinal membrane integrity. A subset of these were associated with disease behavior or location.

CONCLUSIONS

Untargeted lipidomic analyses uncovered perturbations in the circulating human CD lipidome, likely resulting from multiple pathogenic mechanisms. Models using as few as 5 biomarkers had strong disease classifier characteristics, supporting their potential use in diagnosis or prognosis.

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.

Mitochondrial Cholesterol Metabolites in a Bile Acid Synthetic Pathway Drive Nonalcoholic Fatty Liver Disease: A Revised "Two-Hit" Hypothesis

The rising prevalence of nonalcoholic fatty liver disease (NAFLD)-related cirrhosis highlights the need for a better understanding of the molecular mechanisms responsible for driving the transition of hepatic steatosis (fatty liver; NAFL) to steatohepatitis (NASH) and fibrosis/cirrhosis. Obesity-related insulin resistance (IR) is a well-known hallmark of early NAFLD progression, yet the mechanism linking aberrant insulin signaling to hepatocyte inflammation has remained unclear. Recently, as a function of more distinctly defining the regulation of mechanistic pathways, hepatocyte toxicity as mediated by hepatic free cholesterol and its metabolites has emerged as fundamental to the subsequent necroinflammation/fibrosis characteristics of NASH. More specifically, aberrant hepatocyte insulin signaling, as found with IR, leads to dysregulation in bile acid biosynthetic pathways with the subsequent intracellular accumulation of mitochondrial CYP27A1-derived cholesterol metabolites, (25R)26-hydroxycholesterol and 3β-Hydroxy-5-cholesten-(25R)26-oic acid, which appear to be responsible for driving hepatocyte toxicity. These findings bring forth a "two-hit" interpretation as to how NAFL progresses to NAFLD: abnormal hepatocyte insulin signaling, as occurs with IR, develops as a "first hit" that sequentially drives the accumulation of toxic CYP27A1-driven cholesterol metabolites as the "second hit". In the following review, we examine the mechanistic pathway by which mitochondria-derived cholesterol metabolites drive the development of NASH. Insights into mechanistic approaches for effective NASH intervention are provided.

Chenodeoxycholic acid rescues axonal degeneration in induced pluripotent stem cell-derived neurons from spastic paraplegia type 5 and cerebrotendinous xanthomatosis patients

BACKGROUND

Biallelic mutations in CYP27A1 and CYP7B1, two critical genes regulating cholesterol and bile acid metabolism, cause cerebrotendinous xanthomatosis (CTX) and hereditary spastic paraplegia type 5 (SPG5), respectively. These rare diseases are characterized by progressive degeneration of corticospinal motor neuron axons, yet the underlying pathogenic mechanisms and strategies to mitigate axonal degeneration remain elusive.

METHODS

To generate induced pluripotent stem cell (iPSC)-based models for CTX and SPG5, we reprogrammed patient skin fibroblasts into iPSCs by transducing fibroblast cells with episomal vectors containing pluripotency factors. These patient-specific iPSCs, as well as control iPSCs, were differentiated into cortical projection neurons (PNs) and examined for biochemical alterations and disease-related phenotypes.

RESULTS

CTX and SPG5 patient iPSC-derived cortical PNs recapitulated several disease-specific biochemical changes and axonal defects of both diseases. Notably, the bile acid chenodeoxycholic acid (CDCA) effectively mitigated the biochemical alterations and rescued axonal degeneration in patient iPSC-derived neurons. To further examine underlying disease mechanisms, we developed CYP7B1 knockout human embryonic stem cell (hESC) lines using CRISPR-cas9-mediated gene editing and, following differentiation, examined hESC-derived cortical PNs. Knockout of CYP7B1 resulted in similar axonal vesiculation and degeneration in human cortical PN axons, confirming a cause-effect relationship between gene deficiency and axonal degeneration. Interestingly, CYP7B1 deficiency led to impaired neurofilament expression and organization as well as axonal degeneration, which could be rescued with CDCA, establishing a new disease mechanism and therapeutic target to mitigate axonal degeneration.

CONCLUSIONS

Our data demonstrate disease-specific lipid disturbances and axonopathy mechanisms in human pluripotent stem cell-based neuronal models of CTX and SPG5 and identify CDCA, an established treatment of CTX, as a potential pharmacotherapy for SPG5. We propose this novel treatment strategy to rescue axonal degeneration in SPG5, a currently incurable condition.

A Rare Case of Cerebrotendinous Xanthomatosis Associated With a Mutation on COG8 Gene

Cerebrotendinous xanthomatosis (CTX) is a rare hereditary disease described by a mutation in the CYP27A1 gene, which encodes the sterol 27-hydroxylase enzyme involved in the synthesis of bile acid. Accumulation of cholesterol and its metabolite, cholestanol, in multiple body organs causes the symptoms of this disease. In addition, a mutation in the COG8 gene, which encodes a subunit of conserved oligomeric Golgi (COG) complex, causes another rare disorder attributed to type IIh of congenital disorder of glycosylation (CDG). We described a rare case of CTX disorder associated with a mutation on COG8 gene, which presented by unusual symptoms.

Cerebrotendinous Xanthomatosis: A practice review of pathophysiology, diagnosis, and treatment

Cerebrotendinous Xanthomatosis represents a rare and underdiagnosed inherited neurometabolic disorder due to homozygous or compound heterozygous variants involving the CYP27A1 gene. This bile acid metabolism disorder represents a key potentially treatable neurogenetic condition due to the wide spectrum of neurological presentations in which it most commonly occurs. Cerebellar ataxia, peripheral neuropathy, spastic paraparesis, epilepsy, parkinsonism, cognitive decline, intellectual disability, and neuropsychiatric disturbances represent some of the most common neurological signs observed in this condition. Despite representing key features to increase diagnostic index suspicion, multisystemic involvement does not represent an obligatory feature and can also be under evaluated during diagnostic work-up. Chenodeoxycholic acid represents a well-known successful therapy for this inherited metabolic disease, however its unavailability in several contexts, high costs and common use in patients at late stages of disease course limit more favorable neurological outcomes for most individuals. This review article aims to discuss and highlight the most recent and updated knowledge regarding clinical, pathophysiological, neuroimaging, genetic and therapeutic aspects related to Cerebrotendinous Xanthomatosis.

Clinical, electrophysiological, and genetic characteristics of cerebrotendinous xanthomatosis in South Korea

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disorder caused by 27-hydroxylase deficiency. We report the clinical characteristics of six Korean CTX patients. The median age of onset was 22.5 years, the median age at diagnosis was 42 years, and the diagnostic delay was 18.1 years. The most common clinical symptoms were tendon xanthoma and spastic paraplegia. Four of five patients exhibited latent central conduction dysfunction. All patients carried the same mutation in CYP27A1 (c.1214 G>A [p.R405Q]). CTX is a treatable neurodegenerative disorder; however, our results revealed that patients with CTX in Korea might receive the diagnosis after a prolonged delay.    .

Progressive ataxia of cerebrotendinous xanthomatosis with a rare c.255+1G>T splice site mutation: A case report

BACKGROUND

Cerebrotendinous xanthomatosis is an autosomal recessive disorder of lipid metabolism caused by the mutation of the CYP27A1 gene encoding sterol 27-hydroxylase, an essential enzyme for the conversion of cholesterol to chenodeoxycholic and cholic acids. Cerebrotendinous xanthomatosis is a rare neurological disease with a wide range of clinical symptoms that are easily misdiagnosed.

CASE SUMMARY

Here we report the clinical, biochemical, and molecular characterization of a 33-year-old female patient with cerebrotendinous xanthomatosis. The patient developed ataxia and had the typical symptoms of juvenile cataracts, tendon xanthomata, and progressive nervous system dysfunction. Magnetic resonance imaging of the brain revealed bilateral dentate nucleus lesions and white matter abnormalities. This patient was misdiagnosed for 2 years resulting in severe neurological complications. After 2 years of chenodeoxycholic acid treatment, she still presented with ataxia and dysarthria. The pathogenic sites of CYP27A1 were identified as c.255+1G>T and c.1263+1G>T, which were both caused by shear denaturation.

CONCLUSION

Cerebrotendinous xanthomatosis requires a multidisciplinary diagnosis that must be made early to avoid progressive neurological degeneration. c.1263+1G>T is a known mutation, but c.255+1G>T is a rare mutation site.

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.

The Inherited Hypercholesterolemias

Inherited hypercholesterolemias include monogenic and polygenic disorders, which can be very rare (eg, cerebrotendinous xanthomatosis (CTX)) or relatively common (eg, familial combined hyperlipidemia [FCH]). In this review, we discuss familial hypercholesterolemia (FH), FH-mimics (eg, polygenic hypercholesterolemia [PH], FCH, sitosterolemia), and other inherited forms of hypercholesterolemia (eg, hyper-lipoprotein(a) levels [hyper-Lp(a)]). The prevalence, genetics, and management of inherited hypercholesterolemias are described and selected guidelines summarized.

Emerging cellular themes in leukodystrophies

Leukodystrophies are a broad spectrum of neurological disorders that are characterized primarily by deficiencies in myelin formation. Clinical manifestations of leukodystrophies usually appear during childhood and common symptoms include lack of motor coordination, difficulty with or loss of ambulation, issues with vision and/or hearing, cognitive decline, regression in speech skills, and even seizures. Many cases of leukodystrophy can be attributed to genetic mutations, but they have diverse inheritance patterns (e.g., autosomal recessive, autosomal dominant, or X-linked) and some arise from de novo mutations. In this review, we provide an updated overview of 35 types of leukodystrophies and focus on cellular mechanisms that may underlie these disorders. We find common themes in specialized functions in oligodendrocytes, which are specialized producers of membranes and myelin lipids. These mechanisms include myelin protein defects, lipid processing and peroxisome dysfunction, transcriptional and translational dysregulation, disruptions in cytoskeletal organization, and cell junction defects. In addition, non-cell-autonomous factors in astrocytes and microglia, such as autoimmune reactivity, and intercellular communication, may also play a role in leukodystrophy onset. We hope that highlighting these themes in cellular dysfunction in leukodystrophies may yield conceptual insights on future therapeutic approaches.

Selected plasma oxysterols as a potential multi-marker biosignature panel for Behçet's Disease

Clinical, genetic, and medical evidence has shown the inflammatory vasculitis aspect of Behçet's Disease (BD). Whereas oxysterols are vital factors in inflammation and oxidative stress, it is still unknown whether they are involved in the pathophysiology of BD. The current study aims to explore the profile of oxysterols in plasma of BD patients. Thirty patients diagnosed with BD and forty healthy controls matched for age and gender were included. Results showed that the cholestane-3β,5α,6β-triol, 27-hydroxycholesterol (27-OHC) and cholestanol levels were higher in BD than controls. In addition, plasma levels of 7-ketocholesterol (7-KC) and 25-hydroxycholesterol (25-OHC) were lower in BD patient. However, levels of 24S-hydroxycholesterol (24-OHC) did not significantly differ. For BD patients, the plasma 7-KC level was negatively correlated with the BD activity index (BDAI) while 27-OHC was positively correlated with high-sensitivity C-reactive protein (hs-CRP) in patients with active course of the disease. According to ROC analysis, a remarkable increase in the area under the curve (AUC) with a higher sensitivity (Se) and specificity (Sp) for 7-KC, 25-OHC and 27-OHC combined markers was observed. The present study indicated that the identification of the predictive value of these three-selected biomarkers related to oxidative stress and inflammation in patients should lead to a better identification of the etiological mechanism of BD.

Differing clinical features between Japanese siblings with cerebrotendinous xanthomatosis with a novel compound heterozygous CYP27A1 mutation: a case report

Background

Cerebrotendinous xanthomatosis (CTX) is an autosomal-recessive lipid storage disorder caused by mutations in the CYP27A1 gene encoding the key enzyme in the bile acid synthesis, sterol 27-hydroxylase. Here, we report two Japanese CTX siblings with a novel compound heterozygous CYP27A1 mutation, showing different clinical phenotypes and responses to chenodeoxycholic acid (CDCA) therapy.

Case presentation

The proband, a 32-year-old man, who had chronic diarrhea, bilateral cataracts, and xanthomas, demonstrated progressive neurological manifestations including ataxia, and spastic paraplegia during a 5-year follow-up period despite normalization of serum cholestanol after initiation of CDCA treatment. He also exhibited cognitive decline although improvement had been observed at the beginning of treatment. Follow-up brain magnetic resonance imaging (MRI) revealed pronounced progressive atrophy in the cerebellum, in addition to expanding hyperintense lesions in the dentate nuclei, posterior limb of the internal capsule, cerebral peduncles, and inferior olives on T2-weighted images. In contrast, the two-year-younger sister of the proband presented with chronic diarrhea, cataracts, xanthomas, and intellectual disability but no other neurological symptoms at the time of diagnosis. CDCA treatment lead to improvement of cognitive function and there were no characteristic CTX-related MRI features during the follow-up period. The siblings shared a paternally inherited c.1420C > T mutation (p.Arg474Trp) and a maternally inherited novel c.1176_1177delGA mutation, predicting p.(Glu392Asp*20).

Conclusions

Our cases suggest that early diagnosis and subsequent initiation of CDCA treatment are crucial before the appearance of characteristic MRI findings and severe neurological manifestations related to CTX. Further studies are required to elucidate mechanisms responsible for the clinical diversity of CTX and prognostic factors for long-term outcomes following initiation of CDCA treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02711-4.

Cerebrotendinous xanthomatosis without neurological involvement

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessively inherited inborn error of metabolism. Neurological symptoms are considered to be a clinical hallmark of untreated adult patients. We describe a 'milder CTX phenotype', without neurological involvement.

METHODS

We performed a retrospective patient file study in 79 genetically confirmed Dutch patients with CTX (55 patients aged ≥ 21 years) to study the clinical heterogeneity of CTX. We studied the frequency of adult patients with CTX without neurological involvement at diagnosis, in our Dutch cohort, and included a family from South Africa and patients from Italy, USA, Chile and Asia from the literature.

RESULTS

In total, we describe 19 adult patients with CTX from 16 independent families, without neurological symptoms at diagnosis. A relatively small percentage (21%, n = 4) had a history of cataract. The majority, 84% (n = 16), presented with tendon xanthomas as the sole or predominant feature. The majority of patients showed increased plasma cholesterol levels. No correlation was found between this 'milder phenotype', the cholestanol levels and the CYP27A1 genotype. In addition, we describe three novel mutations in the CYP27A1 gene.

CONCLUSIONS

This study shows the clinical heterogeneity of CTX, highlighting the existence of a 'milder phenotype', that is without neurological involvement at diagnosis. Adult patients with CTX may present with tendon xanthomas as the sole or predominant feature, mimicking familial hypercholesterolemia. It is important to realize that the absence of neurological symptoms does not rule out the development of future neurological symptoms. As CTX is a treatable disorder, early diagnosis and initiation of treatment when additional clinical signs occur is therefore essential.

First case series of Polish patients with cerebrotendinous xanthomatosis and systematic review of cases from the 21st century

Cerebrotendinous xanthomatosis (CTX) is an inborn error of metabolism caused by recessive variants in the cytochrome P450 CYP27A1 gene. CTX is said to manifest with childhood-onset chronic diarrhea and the classic triad of juvenile-onset cataracts, Achilles tendons xanthomas, and progressive ataxia. It is currently one of the few inherited neurometabolic disorders amenable to a specific treatment. The diagnosis may be significantly delayed resulting in permanent neurological impairment. A retrospective review of the clinical characteristics and diagnostic findings in case series of six Polish patients with CTX. Additional retrospective review of symptoms and pathogenic variants of 568 CTX available cases and case series from the past 20 years. To the best of our knowledge, this is the widest review of CTX cases reported in years 2000-2021. We report the largest cohort of Polish patients ever published, with the identification of two hot-spot mutations. During the review of available 568 cases, we found significant differences in the clinical phenotypes and the localization of variants within the gene between Asian and non-Asian populations. These findings may facilitate molecular testing in the Polish and Asian populations. Invariably better screening for CTX and wider awareness is needed.

Prevalence of cerebrotendinous xanthomatosis in cases with idiopathic bilateral juvenile cataract in ophthalmology clinics in Turkey

PURPOSE

To determine the prevalence of cerebrotendinous xanthomatosis (CTX) in patients with idiopathic bilateral juvenile cataract in Turkey.

METHODS

In this multicenter, epidemiologic observational study, patients with idiopathic bilateral juvenile cataract (aged ≥1 year at study entry) were identified from the records of 31 ophthalmology clinics. The Mignarri suspicion index determined in all potential CTX patients; blood samples were collected, and genetic testing for CYP27A1 gene mutation was performed. Cholestanol levels of the patients were measured, and those with a level of ≥3.75 μg/mL (threshold value) underwent genetic testing for mutations in the CYP27A1 gene.

RESULTS

CTX was diagnosed in 7 of 452 patients (1.55%) with bilateral juvenile cataract. There was no significant difference between patients with a Mignarri score of <100 (n = 8) and those with a score of ≥100 (n = 19) with respect to cholestanol levels and genetic test results. Genetic testing was undertaken in 27 patients based on elevated cholestanol levels. Of these 27, 7 (26%) had CYP27A1 gene mutations. Of these 7 patients with genetically confirmed CTX, 5 (71%) were in the group with higher Mignarri score (≥100).

CONCLUSIONS

CTX is a treatable condition, and early detection is crucial for avoiding irreversible neurological manifestations. Screening using the Mignarri suspicion index and cholestanol blood levels can be helpful in identifying suspected cases of CTX.

Clinical and biochemical footprints of inherited metabolic diseases. VI. Metabolic dermatoses

Cutaneous signs and symptoms may facilitate the diagnosis or can help in identifying complications or side effects of overtreatment of inherited metabolic diseases. The principal manifestations can be grouped into vascular lesions, ichthyosis, papular and nodular skin lesions, abnormal pigmentation, photosensitivity, skin laxity, hair shaft involvement, and nail abnormalities. We have summarized associations of these cutaneous signs and symptoms in 252 inherited metabolic diseases. This represents the sixth of a series of articles attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement.

Expert opinion on diagnosing, treating and managing patients with cerebrotendinous xanthomatosis (CTX): a modified Delphi study

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a rare, chronic, progressive, neurodegenerative disorder requiring life-long care. Patients with CTX often experience a diagnostic delay. Although early diagnosis and treatment initiation can improve symptoms and prognosis, a standardised approach to diagnosis, treatment and management of patients is not yet established.

AIM

To assess expert opinion on best care practices for patients with CTX using a modified Delphi method.

METHODS

A multidisciplinary group of healthcare professionals with expertise in CTX responded to a 3-round online questionnaire (n = 10 in Rounds 1 and 2; n = 9 in Round 3), containing questions relating to the diagnosis, treatment, monitoring, multidisciplinary care and prognosis of patients with CTX. Determination of consensus achievement was based on a pre-defined statistical threshold of ≥ 70% Delphi panellists selecting 1-2 (disagreement) or 5-6 (agreement) for 6-point Likert scale questions, or ≥ 70% Delphi panellists choosing the same option for ranking and proportion questions.

RESULTS

Of the Round 1 (n = 22), Round 2 (n = 32) and Round 3 (n = 26) questions for which consensus was assessed, 59.1%, 21.9% and 3.8% reached consensus, respectively. Consensus agreement that genetic analyses and/or determination of serum cholestanol levels should be used to diagnose CTX, and dried bloodspot testing should facilitate detection in newborns, was reached. Age at diagnosis and early treatment initiation (at birth, where possible) were considered to have the biggest impact on treatment outcomes. All panellists agreed that chenodeoxycholic acid (CDCA) is a lifetime replacement therapy which, if initiated early, can considerably improve prognosis as it may be capable of reversing the pathophysiological process in CTX. No consensus was reached on the value of cholic acid therapy alone. Monitoring patients through testing plasma cholestanol levels and neurologic examination was recommended, although further research regarding monitoring treatment and progression of the disease is required. Neurologists and paediatricians/metabolic specialists were highlighted as key clinicians that should be included in the multidisciplinary team involved in patients' care.

CONCLUSIONS

The results of this study provide a basis for standardisation of care and highlight key areas where further research is needed to inform best practices for the diagnosis, treatment and management of patients with CTX.

Patients with cerebrotendinous xanthomatosis diagnosed with diverse multisystem involvement

Cerebrotendinous xanthomatosis (CTX) is a lipid storage disease caused by deficiency of sterol 27-hydroxylase enzyme encoded by CYP27A1 gene. This multicenter, cross-sectional descriptive study aimed to document clinical characteristics of CTX patients of different ages, clinical presentations of early-diagnosed patients, and responses to short-term chenodeoxycholic acid (CDCA) treatment. Seven of 11 CTX patients were diagnosed in childhood. Three patients (27%) had neonatal cholestasis, seven (63%) patients had a history of frequent watery defecation started in infantile period, and eight (72.7%) patients had juvenile cataract. Four patients in the adult age group had pyramidal signs and parkinsonism symptoms. The mean Mignarri score at diagnosis was significantly lower in the pediatric patients (267.8 ± 51.4) than in the adult patients (450.0 ± 64.0, p = 0.001). No significant difference was determined between pediatric patients and adult patients regarding plasma cholestanol concentration at diagnosis (p = 0.482). The frequency of defecation decreased with treatment in six children, who had diarrhea at admission. Compared to pretreatment values, patients' body weight and standardized body mass index significantly increased at the 12th month of treatment. In conclusion, Mignarri scores are lower in the pediatric patients than in adult patients since the most determinative signs of the CTX disease are not apparent yet in the childhood. The disease is frequently overlooked in routine practice as the disease presents itself with different clinical combinations both in adults and in children. CTX is potentially a treatable disease; thereby, enhanced awareness is critically important for early diagnosis particularly in children.

Achilles Tendon Xanthoma and Cholestanol Revealing Cerebrotendinous Xanthomatosis: A New Case Report

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disease rarely reported in Africa. Therefore, we report a Moroccan first case report of CTX. A 20-year-old woman was presented in our department for bilateral swelling of the posterior aspect of ankles and the anterior aspect knees with gait disturbances evolving since the age of 7. The patient was the first child of consanguineous marriage. She had bilateral cataracts and developmental delay. Laboratory findings revealed that the plasma cholestanol level was remarkably elevated, and plasma and urine bile alcohol levels were elevated. MRI of ankles showed a bilateral diffuse thickening of the Achilles tendon with hypointense in T1 and heterogeneous hypersignal in T2 with spots in hypersignal in T1 and T2. Brain MRI revealed bilateral and symmetrical T2 hypersignal of dentate nuclei, without white matter signal alterations or cerebral or cerebellar atrophy. A biopsy obtained of the Achilles swelling with a histological study showed an aspect of tendon xanthoma. Hence, the diagnosis of CTX was made. MRI, especially brain MRI, plays an important role in the diagnosis of CTX.

Clinical Diagnosis and Treatment Value of CT Three-Dimensional Imaging of Gynecological Pelvic Blood Vessels

For diseases of the abdominal and pelvic system, especially those of the blood duct system, the main examination methods of the transmission system are color Doppler ultrasound, enhanced CT angiography and digital subtraction angiography (DSA). Among them, DSA is the gold standard of angiography, but it is an invasive examination, which is complicated, time-consuming and laborious, and the skill of intubation is very high. Enhanced 3D-CT blood tube imaging has been gradually used in clinic because of its advantages such as fast imaging speed and wide imaging range. It has good vascular imaging conditions and satisfactory vascular imaging results in all parts of the human body, but this examination is radioactive and is not beneficial to young women of childbearing age, children and frail patients. The purpose of this paper is to further illustrate the value of magnetic resonance angiography (CTA) in displaying pelvic vessels by comparing the three-dimensional model of magnetic resonance angiography (CTA) and magnetic resonance angiography (MRA) in healthy young women. The results showed that for the venous system, CTA usually showed only the internal and external iliac vein, but not for the uterine vein and other branches of the internal and external iliac vein, and almost no imaging for the anterior sacral vein. CE-MRA can not only display 1-4 grade arteries to the same extent, but also show more branches of superior and inferior gluteal arteries, and show more abundant veins, especially presacral veins. For cases such as gynecological pelvic floor surgery, it is necessary to know the vascular network of presacral region before operation. In a word, for clinical diagnosis and treatment value, the 3D-CT imaging is the first choice.

Inborn Errors of Metabolism Associated With Autism Spectrum Disorders: Approaches to Intervention

Increasing evidence suggests that the autism spectrum disorder (ASD) may be associated with inborn errors of metabolism, such as disorders of amino acid metabolism and transport [phenylketonuria, homocystinuria, S-adenosylhomocysteine hydrolase deficiency, branched-chain α-keto acid dehydrogenase kinase deficiency, urea cycle disorders (UCD), Hartnup disease], organic acidurias (propionic aciduria, L-2 hydroxyglutaric aciduria), cholesterol biosynthesis defects (Smith-Lemli-Opitz syndrome), mitochondrial disorders (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes-MELAS syndrome), neurotransmitter disorders (succinic semialdehyde dehydrogenase deficiency), disorders of purine metabolism [adenylosuccinate lyase (ADSL) deficiency, Lesch-Nyhan syndrome], cerebral creatine deficiency syndromes (CCDSs), disorders of folate transport and metabolism (cerebral folate deficiency, methylenetetrahydrofolate reductase deficiency), lysosomal storage disorders [Sanfilippo syndrome, neuronal ceroid lipofuscinoses (NCL), Niemann-Pick disease type C], cerebrotendinous xanthomatosis (CTX), disorders of copper metabolism (Wilson disease), disorders of haem biosynthesis [acute intermittent porphyria (AIP)] and brain iron accumulation diseases. In this review, we briefly describe etiology, clinical presentation, and therapeutic principles, if they exist, for these conditions. Additionally, we suggest the primary and elective laboratory work-up for their successful early diagnosis.