Late-onset spinal form xanthomatosis without brain lesion: a case report

A case of cerebrotendinous xanthomatosis with massive xanthomas but without a considerable increase in serum cholestanol levels

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by mutations in the sterol 27-hydroxylase gene (CYP27A1). Due to the deficiency of 27-hydroxylase, the synthesis of bile acids from cholesterol is impaired and excessive cholestanol accumulates in various tissues, such as the central nervous system, tendons, and lenses. Patients with CTX typically manifest intellectual decline, pyramidal tract symptoms, cerebellar symptoms, tendon xanthomas, juvenile cataracts, neonatal jaundice, chronic diarrhea, osteoporosis, and premature cardiovascular disease. Here, we report the atypical case of a 35-year-old female with CTX having massive xanthomas but without a considerable increase in serum cholestanol levels (3.9 µg/mL). In the differential diagnosis of xanthoma, CTX should not be ruled out even if the serum levels of cholestanol are not high, and genetic testing is necessary to make the appropriate diagnosis.

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.

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

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

Familial variability of cerebrotendinous xanthomatosis lacking typical biochemical findings

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder of bile acid synthesis caused by pathogenic variants in the CYP27A1 gene encoding the mitochondrial enzyme sterol 27-hydroxylase. Patients with CTX can present with a wide range of symptoms, but most often have evidence of tendon xanthomas along with possible cataracts, atherosclerosis, or neurological dysfunction. Regardless of clinical phenotype, CTX patients typically exhibit levels of cholestanol and bile acid precursors in the circulation that are many fold increased over normal control concentrations. Here we report two siblings, one with the rare spinal xanthomatosis phenotype and the other with a very mild form of CTX manifesting as minor tendon xanthomatosis and gastrointestinal complaints who both carry compound heterozygous variants in CYP27A1: NM_000784.3: c.410G > A (p.Arg137Gln) and c.1183C > T (p.Arg395Cys). However, biochemical analysis of these patients revealed normal levels of serum cholestanol and relatively mild elevations of the bile acid precursors 7α-hydroxy-4-cholesten-3-one and 7α,12α-dihydroxy-4-cholesten-3-one. The atypical biochemical presentation of these cases represents a diagnostic challenge for a disorder once thought to have a sensitive biomarker in cholestanol and highlight the need for thorough investigation of patients with symptomatology consistent with CTX that includes bile acid precursor biochemical testing and molecular analysis.

The clinical and imaging features of cerebrotendinous xanthomatosis: A case report and review of the literature

RATIONALE

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid deposition disorder characterized by systemic signs and neurological dysfunction. The radiological features of CTX are infrequently summarized in the literature.

PATIENT CONCERNS

We described a 40-year-old male patient who repeatedly engaged in wrestling matches and presented with progressive difficulty in walking and reduced balance with egg-sized, hard, smooth, and painless masses in both ankles.

DIAGNOSIS

Neuroimaging examination showed abnormalities both supra- and infratentorially. Bilateral ankle joint magnetic resonance imaging showed bilateral xanthomata of the Achilles tendon. The diagnosis was confirmed by the detection of a sterol 27-hydroxylase gene mutation.

INTERVENTIONS

The patient was treated with chenodeoxycholic acid (250 mg 3 times per day).

OUTCOMES

To date, the patient's bilateral xanthomas of the Achilles tendon have begun to diminish, and his neurological impairment has not deteriorated further but has not yet improved.

LESSONS

We report a rare case of CTX and summarize the clinical and imaging features of this disease. Our findings suggest that the abnormal signals in the dentate nucleus or a long spinal cord lesion involving the central and posterior cord, combined with tendon xanthoma, are important clues for the diagnosis of CTX.

Spinal cerebrotendinous xanthomatosis: A case report and literature review

Background

Classic cerebrotendinous xanthomatosis (CTX; OMIM #213700) manifests with chronic diarrhea, juvenile cataracts, tendon xanthomas and neurological symptoms. It is due to biallelic inactivation of CYP27A1 wich leads to cholestanol accumulation in the central nervous system, eyes and tendons. Less commonly, the disease can present in young adults as spastic paraparesis in the absence of xanthomas.

Case presentation

We report a 38-year old woman who presented with chronic diarrhea and progressive spastic paraparesis in her twenties. Brain magnetic resonance imaging (MRI) showed cerebral atrophy with diffuse periventricular white matter hyperintensities. Spinal MRI was normal. CYP27A1 gene sequencing confirmed the diagnosis of CTX. Chenodeoxycholic acid (CDCA) treatment was introduced with remission of diarrhea. Unfortunately, the treatment had to be discontinued several times and the patient developed psychosis and an severe ataxospastic gait. Spinal MRI revealed new linear hyperintensities of the corticospinal and gracile tracts. Thirty-three spinal CTX patients were identified by searching in Pubmed, EMBASE™ and Web of Science databases. All patients presented pyramidal signs and 48% had dorsal column signs. Juvenile cataracts were described in 78% of patients, chronic diarrhea in 65%, and tendon xanthomas in 31%. Disease improvement or stabilization with chenodeoxycholic acid was observed in 69% of patients. A higher prevalence of the Arg395Cys allele was observed in patients with spinal CTX as compared to CTX in general (ᵡ²; p < 0.00001).

Conclusions

The diagnosis of spinal CTX can be easily missed or delayed in absence of xanthomas. There is a higher prevalence of the Arg395Cys allele in spinal CTX as compared to classic childhood-onset CTX. CDCA treatment seems to stabilize or improve clinical symptoms in most patients. However, as seen in our patient and in two previously reported cases, sudden interruption of CDCA may lead to irreversible neurological complications.

A Late-onset and Relatively Rapidly Progressive Case of Pure Spinal Form Cerebrotendinous Xanthomatosis with a Novel Mutation in the CYP27A1 Gene

A 61-year-old Japanese man with the pure spinal form of cerebrotendinous xanthomatosis developed dysesthesia of the lower limbs and gait disturbance at 57 years of age. At 61 years old, he was unable to walk without support. A neurological examination showed spasticity and sensory disturbance in the lower limbs. Spinal MRI showed long hyperintense lesions involving the lateral and posterior funiculus in the cervical and thoracic cord on T2-weighted images. His serum cholestanol level was markedly elevated. A CYP27A1 gene analysis identified two missense variants, p.R474W, and a novel p.R262C variant. Combination therapy with chenodeoxycholic acid and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase decreased his serum cholestanol level.

A Late-onset and Relatively Rapidly Progressive Case of Pure Spinal Form Cerebrotendinous Xanthomatosis with a Novel Mutation in the CYP27A1 Gene

A 61-year-old Japanese man with the pure spinal form of cerebrotendinous xanthomatosis developed dysesthesia of the lower limbs and gait disturbance at 57 years of age. At 61 years old, he was unable to walk without support. A neurological examination showed spasticity and sensory disturbance in the lower limbs. Spinal MRI showed long hyperintense lesions involving the lateral and posterior funiculus in the cervical and thoracic cord on T2-weighted images. His serum cholestanol level was markedly elevated. A CYP27A1 gene analysis identified two missense variants, p.R474W, and a novel p.R262C variant. Combination therapy with chenodeoxycholic acid and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase decreased his serum cholestanol level.

Nationwide survey on cerebrotendinous xanthomatosis in Japan

Cerebrotendinous xanthomatosis (CTX) is likely to be underdiagnosed and precise epidemiological characteristics of CTX are largely unknown as knowledge on the disorder is based mainly on case reports. We conducted a nationwide survey on CTX to elucidate the frequency, clinical picture, and molecular biological background of Japanese CTX patients. In this first Japanese nationwide survey on CTX, 2541 questionnaires were sent to clinical departments across Japan. A total of 1032 (40.6%) responses were returned completed for further analysis. Forty patients with CTX (50.0% male) were identified between September 2012 and August 2015. The mean age of onset was 24.5 ± 13.6 years, mean age at diagnosis was 41.0 ± 11.6 years, and corresponding mean duration of illness from onset to diagnosis was 16.5 ± 13.5 years. The most common initial symptom was tendon xanthoma, followed next by spastic paraplegia, cognitive dysfunction, cataract, ataxia, and epilepsy. The most predominant mutations in the CYP27A1 gene were c.1214G> A (p.R405Q, 31.6%), c.1421G> A (p.R474Q, 26.3%), and c.435G> T (p.G145=, 15.8%). Therapeutic interventions that included chenodeoxycholic acid, HMG-CoA reductase inhibitor, and LDL apheresis reduced serum cholestanol level in all patients and improved clinical symptoms in 40.5% of patients. Although CTX is a treatable neurodegenerative disorder, our nationwide survey revealed an average 16.5-year diagnostic delay. CTX may be underdiagnosed in Japan, especially during childhood. Early diagnosis and treatment are essential to improve the prognosis of CTX.

Nationwide survey on cerebrotendinous xanthomatosis in Japan

Cerebrotendinous xanthomatosis (CTX) is likely to be underdiagnosed and precise epidemiological characteristics of CTX are largely unknown as knowledge on the disorder is based mainly on case reports. We conducted a nationwide survey on CTX to elucidate the frequency, clinical picture, and molecular biological background of Japanese CTX patients. In this first Japanese nationwide survey on CTX, 2541 questionnaires were sent to clinical departments across Japan. A total of 1032 (40.6%) responses were returned completed for further analysis. Forty patients with CTX (50.0% male) were identified between September 2012 and August 2015. The mean age of onset was 24.5 ± 13.6 years, mean age at diagnosis was 41.0 ± 11.6 years, and corresponding mean duration of illness from onset to diagnosis was 16.5 ± 13.5 years. The most common initial symptom was tendon xanthoma, followed next by spastic paraplegia, cognitive dysfunction, cataract, ataxia, and epilepsy. The most predominant mutations in the CYP27A1 gene were c.1214G> A (p.R405Q, 31.6%), c.1421G> A (p.R474Q, 26.3%), and c.435G> T (p.G145=, 15.8%). Therapeutic interventions that included chenodeoxycholic acid, HMG-CoA reductase inhibitor, and LDL apheresis reduced serum cholestanol level in all patients and improved clinical symptoms in 40.5% of patients. Although CTX is a treatable neurodegenerative disorder, our nationwide survey revealed an average 16.5-year diagnostic delay. CTX may be underdiagnosed in Japan, especially during childhood. Early diagnosis and treatment are essential to improve the prognosis of CTX.

Bilateral Femoral Neck Fractures in Cerebrotendinous Xanthomatosis Treated by Hip Arthroplasties: The First Case Report and Literature Review

Introduction

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid storage disease caused by mutations of the CYP27A1 gene and deficiency of the sterol-27-hydroxylase enzyme in bile acid biosynthesis. It is characterized by the accumulation of cholestanol and bile alcohols in plasma, the formation of xanthomatous lesions in various tissues, and organ degeneration. This disorder is also associated with osteoporosis and increased risk of fracture. To date, only two CTX patients with femoral neck fractures have been reported. Neither was treated by arthroplasties, and the operative outcomes are lacking.

Case Report

We report the case of a 46-year-old Thai female who presented with consecutive bilateral femoral neck fractures following minor trauma within a 3-year period and received cementless bipolar hemiarthroplasties. Her phenotypic expression included Achilles tendon masses, childhood-onset cataracts, intellectual disability, and cerebellar ataxia. A brain computed tomography showed non-enhancing hypodense lesions in the bilateral cerebellar hemispheres with mild brain atrophy. Histopathology from an Achilles tendon biopsy revealed tendinous xanthoma and molecular analysis confirmed a homozygous nonsense mutation, c.1072C>T (p.Gln358Ter), in exon 6 of the CYP27A1 gene. The intra-operative crack of a calcar femorale was a major complication during both prosthetic insertion surgeries and warranted cerclage wiring. At the 7-month follow-up of the right hip and the 41-month follow-up of the left hip, postoperative radiographs showed well-fixed and well-aligned prostheses. Independent household ambulation could be resumed with Harris hip scores of 81 points equally.

Conclusion

CTX is associated with osteoporosis, and middle-aged patients could present with femoral neck fracture following minor trauma. Cementless bipolar hemiarthroplasty for a totally displaced fracture is justified for a patient who has cognitive impairment. Intra-operative fracture is a major complication during prosthetic insertion and warrants cerclage wiring to achieve predictable bone healing and a satisfactory result.

Bilateral Femoral Neck Fractures in Cerebrotendinous Xanthomatosis Treated by Hip Arthroplasties: The First Case Report and Literature Review

Introduction:

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid storage disease caused by mutations of the CYP27A1 gene and deficiency of the sterol-27-hydroxylase enzyme in bile acid biosynthesis. It is characterized by the accumulation of cholestanol and bile alcohols in plasma, the formation of xanthomatous lesions in various tissues, and organ degeneration. This disorder is also associated with osteoporosis and increased risk of fracture. To date, only two CTX patients with femoral neck fractures have been reported. Neither was treated by arthroplasties, and the operative outcomes are lacking.

Case Report:

We report the case of a 46-year-old Thai female who presented with consecutive bilateral femoral neck fractures following minor trauma within a 3-year period and received cementless bipolar hemiarthroplasties. Her phenotypic expression included Achilles tendon masses, childhood-onset cataracts, intellectual disability, and cerebellar ataxia. A brain computed tomography showed non-enhancing hypodense lesions in the bilateral cerebellar hemispheres with mild brain atrophy. Histopathology from an Achilles tendon biopsy revealed tendinous xanthoma and molecular analysis confirmed a homozygous nonsense mutation, c.1072C>T (p.Gln358Ter), in exon 6 of the CYP27A1 gene. The intra-operative crack of a calcar femorale was a major complication during both prosthetic insertion surgeries and warranted cerclage wiring. At the 7-month follow-up of the right hip and the 41-month follow-up of the left hip, postoperative radiographs showed well-fixed and well-aligned prostheses. Independent household ambulation could be resumed with Harris hip scores of 81 points equally.

Conclusion:

CTX is associated with osteoporosis, and middle-aged patients could present with femoral neck fracture following minor trauma. Cementless bipolar hemiarthroplasty for a totally displaced fracture is justified for a patient who has cognitive impairment. Intra-operative fracture is a major complication during prosthetic insertion and warrants cerclage wiring to achieve predictable bone healing and a satisfactory result.

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

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

Pathophysiology of cerebrotendinous xanthomatosis

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