Chronic diarrhoea as a dominating symptom in two children with cerebrotendinous xanthomatosis

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.

Movement Disorders and the Gut: A Review

There is a close link between multiple movement disorders and gastrointestinal dysfunction. Gastrointestinal symptoms may precede the development of the neurologic syndrome or may arise following the neurologic presentation. This review will provide an overview of gastrointestinal accompaniments to several well-known as well as lesser known movement disorders. It will also highlight several disorders which may not be considered primary movement disorders but have an overlapping presentation of both gastrointestinal and movement abnormalities.

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.

Cholestasis as a dominating symptom of patients with CYP27A1 mutations: An analysis of 17 Chinese infants

BACKGROUND

CYP27A1 is the disease-causing gene of cerebrotendinous xanthomatosis (CTX). As a treatable lipid storage disease, early treatment can improve the prognosis. However, CTX patients reported in the literature are mostly adult patients; the phenotype spectrum of CTX in the infantile population remains elusive.

OBJECTIVE

We aimed to investigate the phenotype spectrum of infants who carried pathogenic or likely pathogenic variants in the CYP27A1 gene and were suspected of having CTX.

METHODS

From June 2014 to May 2020, infants with pathogenic or likely pathogenic variants in CYP27A1 gene were enrolled, who underwent next-generation sequencing or Sanger sequencing in Children's Hospital of Fudan University. Patient characteristics, clinical treatments and outcomes were extracted from electronic medical records.

RESULTS

A total of 17 patients with an average onset age of 8 (1-42) days were found. The average diagnosis age was ten months. Cholestasis was the dominant symptom of these infants. Thirteen variants were detected, of which c.379C > T was a hotspot variant (26.5% alleles, 9/34). Cholestatic CTX is usually underestimated, but it could be severe or even fatal in infancy. For outcomes, 5 suffered from liver failure (36%, 5/14), 1 still showed cholestasis (7%, 1/14), 7 were asymptomatic (50%, 7/14), and 1 presented seizure and developmental delay in later childhood (7%, 1/14).

CONCLUSION

Based on this infantile cohort, we concluded that it is necessary to consider the possibility of CTX caused by CYP27A1 gene variants for infants with cholestasis.

Cerebrotendinous xanthomatosis-associated diarrhea and response to chenodeoxycholic acid treatment

BACKGROUND

In patients with cerebrotendinous xanthomatosis (CTX), chronic diarrhea is one of the earliest and main symptoms of the disease. In the current study, we evaluated the characteristics of the diarrhea and its response to chenodeoxycholic acid (CDCA) therapy in a cohort of Dutch CTX patients.

METHODS

We performed a retrospective review of medical records for 33 genetically confirmed CTX patients, and abstracted the characteristics of the diarrhea and the response to CDCA therapy (15 mg/kg/day up to 750 mg/day). The Bristol Stool Scale (BSS) was used for qualitative characterization of the stool.

RESULTS

Twenty-five patients had diarrhea documented at baseline (76%). Of these patients, 10 had diarrhea rated as 6 (fluffy pieces with ragged edges, a mushy stool), and 6 had diarrhea rated as 7 (watery, no solid pieces, entirely liquid) using the BSS. In 10 patients for whom data were recorded, the median stool frequency at baseline was 3 per day (range 2-6 per day). The response rate with CDCA for diarrhea resolution was 100% based on at least one post-baseline visit without diarrhea and 95% as assessed at the first post-baseline visit. In 68% of cases resolution was complete and sustained as no episodes of diarrhea were documented for follow-up periods as long as 25 years.

CONCLUSIONS

Chronic diarrhea persisting for years without spontaneous remission is a common feature of CTX at diagnosis. Chenodeoxycholic acid is an effective treatment for symptomatic relief of diarrhea in patients with CTX.

Patients with Lately Diagnosed Cerebrotendinous Xanthomatosis

Objectives: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive inborn lipid storage disorder due to various pathogenic mutations in the CYP27A1 gene. Although the symptoms begin commonly in infancy, CTX diagnosis is often delayed. In this study, we report 7 Turkish CTX patients who had a delayed diagnosis despite early clinical signs and belonged to 6 unrelated families. Methods: We have retrospectively evaluated clinical, laboratory, imaging, and genetic findings of CTX patients, which were collected from 2 centers specialized in movement disorders: the Department of Neurology, Faculty of Medicine, Istanbul University, and the Department of Neurology, Faculty of Medicine, Mersin University. Results: All patients were diagnosed with CTX after neurological symptom development, and their mean age at diagnosis was 38.7 ± 9.6 years, despite a mean onset age of 12.4 ± 10.6 years. The mean follow-up period was 28 months (range: 3–60 months). The most common initial clinical abnormalities in our cohort were unexplained chronic diarrhea (42%), febrile convulsion (42%), juvenile cataract (85%), childhood depression and autism (14%), parkinsonism (14%), and intellectual disability (100%). The most prominent neurological findings were the pyramidal-cerebellar syndrome (85%) and extrapyramidal signs (42%). All patients were genetically confirmed. Serum cholestanol levels were elevated in all patients and decreased after chenodeoxycholic acid (CDCA) treatment in 6 patients. Conclusion: This cohort is the largest CTX case series in Turkey. All cases showed improvement in gastrointestinal symptoms as a response to CDCA treatment and stabilization on neurological symptoms, i.e., no further progression of neurological abnormalities were noted during this treatment. Therefore, early diagnosis and treatment is crucial in preventing clinical deterioration.

Early diagnosed cerebrotendinous xanthomatosis patients: clinical, neuroradiological characteristics and therapy results of a single center from Turkey

Cerebrotendinous xanthomatosis (CTX) is a lipid storage disorder caused by defective sterol 27-hydroxylase activity. In spite of subtle clinical signs beginning from childhood, CTX is generally diagnosed lately. The aim of this study is to evaluate clinical, neuroradiological findings and therapy responses of pediatric CTX patients and raise awareness to early features of disease. Patients who were molecularly diagnosed as CTX before 18 years of age were included in study. Clinical, epidemiological, radiological and genotypic features of patients and chenodeoxycholic acid (CDCA) therapy responses were reviewed retrospectively. Six patients were enrolled in the study. The mean age of diagnosis was 11.1 ± 4.5 years. Apart from previous studies, predominance of cerebellar signs over pyramidal signs, peripheral neuropathy with demyelinating neuropathy in majority of patients and pathological brain imaging findings despite young ages of patients were observed. Intention tremor was the consisting finding of all patients. Optic disc drusen was initially reported in one patient. Skeletal system involvement as coarse extremities, deformities and early osteoporosis was recognized in four patients. CDCA therapy improved or at least stabilized neurological functions in all patients. This study is the first CTX series from Turkey and performed among only in early diagnosed patients with a therapy follow-up contrary to limited data in the literature. We suggest that, awareness of intention tremor and ataxic gait in addition to mental retardation, peripheral neuropathy and early osteoporosis can be suspicious for CTX and lead diagnosis. Early treatment can provide stability and may also ameliorate existing neurological findings.

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.

Cerebrotendinous xanthomatosis: a comprehensive review of pathogenesis, clinical manifestations, diagnosis, and management

Cerebrotendinous xanthomatosis (CTX) OMIM#213700 is a rare autosomal-recessive lipid storage disease caused by mutations in the CYP27A1 gene; this gene codes for the mitochondrial enzyme sterol 27-hydroxylase, which is involved in bile acid synthesis. The CYP27A1 gene is located on chromosome 2q33-qter and contains nine exons. A CYP27A1 mutation leads to decreased synthesis of bile acid, excess production of cholestanol, and consequent accumulation of cholestanol in tissues. Currently there is no consensus on the prevalence of CTX, one estimate being <5/100,000 worldwide. The prevalence of CTX due to the CYP27A1 mutation R362C alone is approximately 1/50,000 in Caucasians. Patients with CTX have an average age of 35 years at the time of diagnosis and a diagnostic delay of 16 years. Clinical signs and symptoms include adult-onset progressive neurological dysfunction (i.e., ataxia, dystonia, dementia, epilepsy, psychiatric disorders,peripheral neuropathy, and myopathy) and premature non-neurologic manifestations (i.e., tendon xanthomas, childhood-onset cataracts, infantile-onset diarrhea, premature atherosclerosis, osteoporosis, and respiratory insufficiency). Juvenile cataracts, progressive neurologic dysfunction, and mild pulmonary insufficiency are unique symptoms that distinguish CTX from other lipid storage disorders including familial dysbetalipoproteinemia, homozygous familial hypercholesterolemia, and sitosterolemia, all of which might also present with xanthomas and cardiovascular diseases. Brain magnetic resonance imaging (MRI) shows bilateral lesions in the dentate nucleus of the cerebellum and mild white matter lesions. The classical symptoms and signs, namely elevated levels of cholestanol and bile alcohols in serum and urine, brain MRI, and the mutation in the CYP27A1 gene confirm the diagnosis of CTX. Early diagnosis and long-term treatment with chenodeoxycholic acid (750 mg/d) improve neurological symptoms and contribute to a better prognosis.

Clinical and molecular genetic characteristics of patients with cerebrotendinous xanthomatosis

Cerebrotendinous xanthomatosis (CTX) is a lipid storage disease caused by a deficiency of the mitochondrial enzyme 27-sterol hydroxylase (CYP 27), due to mutations in its gene. In this study we report on mutations in 58 patients with CTX out of 32 unrelated families. Eight of these were novel mutations, two of which were found together with two already known pathogenic mutations. Twelve mutations found in this patient group have been described in the literature. In the patients from 31 families, mutations were found in both alleles. In the literature, 28 mutations in 67 patients with CTX out of 44 families have been described. Pooling our patient group and the patients from the literature together, 37 different mutations in 125 patients out of 74 families were obtained. Identical mutations have been found in families from different ethnic backgrounds. In 41% of all the patients, CYP 27 gene mutations are found in the region of exons 6-8. This region encodes for adrenodoxin and haem binding sites of the protein. Of these 125 patients, a genotype-phenotype analysis was done for 79 homozygous patients harbouring 23 different mutations, out of 45 families. The patients with compound heterozygous mutations were left out of the genotype-phenotype analysis. The genotype-phenotype analysis did not reveal any correlation.