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.

Case Report: a novel CYP27A1 gene variant in a patient with cerebrotendinous xanthomatosis with unusual clinical findings.

PURPOSE/AIM OF THE STUDY: Cerebrotendinous xanthomatosis is a disease with important clinical and molecular heterogeneity. CYP27A1 gene was described as the cause of these defects, with more than 50 mutations involved in the disease. The objective of this study was to carry out a genetic study and a clinical description of a patient with unusual clinical manifestation of the disease. MATERIALS AND METHODS: DNA sequencing was used for the evaluation of CYP27A1 exon sequences and their intron/exon boundaries. Copy number variants were calculated using a method based on depth of sequencing coverage. In addition, the potential effects of the missense variants were analyzed, and an in-silico protein modeling tool was used. Finally, a patient case description was performed in order to evaluate patient phenotype according to genetic results. RESULTS: Patient clinical features indicate the possible presence of a disease milder phenotype. When analyzing the CYP27A1 gene, patient presents a pathogenic variant (p.Arg474Trp) and a variant of unknown significance (p.Met130Ile) that causes a slight modification of the protein functional structure. This variant in homozygosis or double or compound heterozygosis together with other biallelic pathological mutations may be the cause of the clinical phenotype observed in the reported patient. CONCLUSIONS: Clinical manifestations of cerebrotendinous xanthomatosis are heterogeneous, and sometimes wrongly suggest the presence of other diseases. Some patients seem to present an "incomplete" phenotype, which could be redefined as a variant of the disease with further studies. The evaluation of new mutations allows for earlier diagnosis and greater effectiveness in its treatment.

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.

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.

Xantoma del tendón de aquiles bilateral: debut de xantomatosis cerebrotendinosa / Bilateral achilles tendon xanthoma: cerebrotendinous xanthomatosis debut

OBJETIVO Presentación de un inusual caso de xantomatosis cerebrotendinosa en un paciente de edad cuya primera manifestación fueron xantomas bilaterales del tendón de Aquiles. MATERIAL Y MÉTODOS Mujer de 62 años, que presenta tumoraciones, que presenta tumoraciones sólidas y polilobuladas, en la cara posterior de ambos tendones de Aquiles de 8 años de evolución. El diagnóstico se realizó mediante el hallazgo de hiperlipidemia y estudio genético. Se realió la exóresis quirúrgica parcial de las tumoraciones. RESULTADOS A los 5 años de la cirugía del pie izquierdo y 4 años del pie derecho la paciente estaba asintomática. Presentaba una fuerza para la flexión plantar bilateral de 5/5, pudiendo caminar y subir escaleras sin molestias. Presentaba una escala AOFAS de 85 y 90 puntos en el pie izquierdo y derecho, respectivamente. No hubo recidivas. DISCUSIÓN Los xantomas son depósitos de colesterol en el tejido conectivo de la piel, tendones o fascia, como resultado de una hiperlipoproteinemia. La importancia del caso radica en su sospecha diagnóstica, ya que la xantomatosis cerebrotendinosa suele manifestarse en pacientes de menos de 30 años de edad y en los que se ha recomendado la resección radical de las tumoraciones, e incluso del tendón, debido a las frecuentes recidivas. CONCLUSIÓN En pacientes de mayor edad con lesiones que infiltran el tendón, se puede optar por un tratamiento menos agresivo con un buen resultado clínico.

OBJETIVE Presentation of an unusual case of cerebrotendinous xanthomatosis in an elderly patient whose first manifestation was bilateral Achilles tendon xanthomas. MATERIAL AND METHODS 62-year-old woman presenting solid and polylobed tumors on the posterior aspect of both Achilles tendons for eight years. The diagnosis was made by means of hyperlipidemia and a genetic study. Surgical partial excision of the tumors was performed. RESULTS Five years after surgery on the left foot and four years after the right foot, the patient was asymptomatic. Bilateral plantar flexion force was 5/5, The patient was able to walk and climb stairs without discomfort. AOFAS score was 85 and 90 on the left and right feet, respectively. There were no recurrences. DISCUSSION Xanthomatosis is a genetic alteration with deposits of cholesterol in connective tissue of the skin, tendons or fascia, because of hyperlipoproteinemia. The importance of the present case lies in its diagnostic suspicion, since cerebrotendinous xanthomatosis manifests usually in patients under 30 years of age and in whom radical resection of tumors, and even of the tendon, has been recommended due to frequent recurrences . CONCLUSION In older patients with tumors that infiltrate the tendon, a less aggressive treatment can be chosen with a good clinical result.

Xantomatosis cerebrotendinosa: Reporte de un caso en el Perú: Evaluación clínica integral y estudios de neuroimágenes / Cerebrotendinous Xanthomatosis: Report of a case in Peru: Comprehensive clinical evaluation and neuroimaging studies

Se presenta el caso de una paciente de 73 años de edad que, a los 30 años aproximadamente, comenzó a quejarse de dolor al caminar, localizando la molestia a nivel de las regiones aquilianas, con subsecuente aumento de volumen; al paso del tiempo, estas molestias la obligaron a efectuar consulta médica. Los análisis de laboratorio mostraron severa dislipidemia mixta. Al lado de información de significativa declinación cognitiva, provista por familiares (vgr., (i.e., olvidos frecuentes, desorientación, atención disminuida, concentración pobre), hubo evidencia de ánimo fluctuante, labilidad emocional, crisis ansiosas evolucionando hacia ataques de pánico. El test minicognitivo de Folstein, mostró severo estado demencial y en el examen neurológico se constataron ataxia cerebelosa y signos de piramidalismo parcial. El examen oftalmológico puso en evidencia xantelasmas, cataratas y un denso arco senil. El estudio del cerebro con resonancia magnética (RM) mostró el daño encefálico y signos sugestivos de depósitos del colastenol en el SNC. La presencia de xantomas , los hallazgos oftalmológicos, la demencia definidamente progresiva y la ataxia cerebelosa fueron hallazgos clínicos que permitieron establecer el diagnóstico de xantomatosis cerebrotendinosa.

The case of a 73 years-old woman that, since approximately the age of 30 years started to complain of pain when walking, is presented. The symptom was mainly located in the acchillean regions which, as time advanced, showed gradual volume increase and, finally, forced her to seek medical evaluation. Accompanying relatives reported a several years’ history of gradually increasing cognitive difficulties (i.e., forgetfulness, disorientation, poor attention and concentration), fluctuating mood (from periods of good humor switching to sudden episodes of sadness and crying spells), emotional lability and anxiety crises evolving into brief panic attacks. The Mini-cognitive Fenton Test confirmed severe dementia and the neurological evaluation showed cerebellar ataxia and partial pyramidalism. The ophthalmological examination revealed xanthelasmas, cataracts and dense arcus senilis. Xanthomas were detected in the Achillean tendons of both lower extremities. Auxiliary laboratory and densitometric tests demonstrated mixed dyslipidemia and dorsal-lumbar osteoporosis, respectively, and magnetic resonance imaging of the brain (RMC) confirmed SNC damage and suggested deposits of cholestenol, thus confirming the diagnosis of Cerebroitendinous Xanthomatosis.

A Treatable Rare Cause of Progressive Ataxia and Palatal Tremor.

Background: Cerebrotendinous xanthomatosis is a rare autosomal recessive neurometabolic disorder characterized by chronic diarrhea, tendon xanthomas, juvenile cataracts, and neurological symptoms. Case Report: An adult patient with cerebrotendinous xanthomatosis exhibited ataxia and palatal tremor in the absence of tendon xanthomas and cataracts. Discussion: The importance of this case resides on the fact that cerebrotendinous xanthomatosis should be considered as a possible etiology of the syndrome of progressive ataxia with palatal tremor, even in the absence of tendon xanthomas and cataracts. Early diagnosis is critical to the institution of specific treatment with chenodeoxycholic acid.

Clinical and molecular characterization of hereditary spastic paraplegias: A next-generation sequencing panel approach.

BACKGROUND: Molecular diagnosis of hereditary spastic paraplegias (HSP) is a difficult task due to great clinical and genetic heterogeneity. We aimed to characterize clinical and molecular findings of HSP families from Rio Grande do Sul, Brazil; and to evaluate the diagnostic yield of a next-generation sequencing (NGS) panel with twelve HSP-related genes. METHODS: A consecutive series of HSP index cases with familial recurrence of spasticity, consanguinity or thin corpus callosum (TCC) were included in this cross-sectional study. RESULTS: Among the 29 index cases, 51.7% (15/29) received at least a likely molecular diagnosis, and 48.3% (14/29) a defined diagnosis. NGS panel diagnostic yield was 60% for autosomal dominant HSP (6/10, all SPG4), 47.4% for autosomal recessive HSP (9/19: 5 SPG11, 2 SPG7, 1 SPG5 and 1 cerebrotendinous xanthomatosis), and 50% for patients with TCC (3/6, all SPG11). Remarkably, 2/6 SPG11 patients presented keratoconus, and tendon xanthomas were absent in the patient with cerebrotendinous xanthomatosis. CONCLUSION: A likely molecular diagnosis was obtained for more than half of families with the NGS panel, indicating that this approach could be employed as a first-line investigation for HSP. SPG4 is the most frequent form of autosomal dominant and SPG11 of autosomal recessive HSP in Southern Brazil.

Novel splice-affecting variants in CYP27A1 gene in two Chilean patients with Cerebrotendinous Xanthomatosis.

Cerebrotendinous Xanthomatosis (CTX), a rare lipid storage disorder, is caused by recessive loss-of-function mutations of the 27-sterol hydroxylase (CYP27A1), producing an alteration of the synthesis of bile acids, with an accumulation of cholestanol. Clinical characteristics include juvenile cataracts, diarrhea, tendon xanthomas, cognitive impairment and other neurological manifestations. Early diagnosis is critical, because treatment with chenodeoxycholic acid may prevent neurological damage. We studied the CYP27A1 gene in two Chilean CTX patients by sequencing its nine exons, exon-intron boundaries, and cDNA from peripheral blood mononuclear cells. Patient 1 is a compound heterozygote for the novel substitution c.256-1G > T that causes exon 2 skipping, leading to a premature stop codon in exon 3, and for the previously-known pathogenic mutation c.1183C > T (p.Arg395Cys). Patient 2 is homozygous for the novel mutation c.1185-1G > A that causes exon 7 skipping and the generation of a premature stop codon in exon 8, leading to the loss of the crucial adrenoxin binding domain of CYP27A1.

Cerebrotendinous xanthomatosis: Possibility of founder mutation in CYP27A1 gene (c.526delG) in Eastern Indian and Surinamese population.

Cerebrotendinous xanthomatosis is a lipid storage disease characterized by diarrhea, cataract, tendon xanthoma and neurological regression if untreated. CYP27A1 is the only gene in which mutations are known to cause Cerebrotendinous xanthomatosis. We report two Indian families from different regions of India who underwent molecular testing of CYP27A1. The first family from Eastern India consisting of two affected individuals was found to have the c.526delG homozygous mutation in exon 3, previously reported from our laboratory, also in a patient from Eastern India. However the second affected individual from Southern India that we studied and two previously reported cases from Northern India have different mutations. Interestingly the only previous report of c.526delG mutation was in a Surinamese individual from the Netherlands. To date most of the pathogenic mutations for Cerebrotendinous xanthomatosis have been confined to single population except for R362C mutation which was reported from the Netherlands and the USA (Black). To our knowledge this is the second causal mutation for Cerebrotendinous xanthomatosis which has been reported in two different populations. As human trading was prevalent from Eastern India to Surinam by the Dutch settlers this mutation might suggest a common founder mutation in these populations.

Xantomatose cerebrotendínea: relato de dois casos / Cerebrotendinous xanthomatosis: a two-case report

Xantomatose cerebrotendínea é rara condição de natureza genética, na qual se observa redução na atividade da enzima hepática 27-hidroxilase, envolvida no metabolismo e excreção do colesterol. Consequentemente, depósitos de material lipídico (colesterol/colestanol) acumulam-se em diferentes regiões do organismo, principalmente tendões, sistema nervoso central e cristalino. Relatamos dois casos da doença em duas irmãs, mostrando os principais achados de imagem.

Cerebrotendinous xanthomatosis is a rare genetic disorder characterized by a decrease in activity of the hepatic sterol 27-hydroxylase involved in the cholesterol metabolism and excretion. Consequently, lipid (cholesterol/cholestanol) deposition is observed in different regions of the body, especially tendons, central nervous system and eye lens. The present report describes the cases of two sisters affected by this disease, highlighting the main imaging findings.