Vanishing White Matter Disease Research Articles

Genotypic and phenotypic characteristics of juvenile/adult onset vanishing white matter: a series of 14 Chinese patients.

Vanishing white matter (VWM) is one of the most prevalent leukoencephalopathies and is caused by recessive mutations in gene eIF2B1-5. The onset may vary from an antenatal disorder that is rapidly fatal to an adult-onset disorder with chronic progressive deterioration. Based on a comprehensive study of 14 juvenile/adult patients diagnosed in our department as well as a review of 71 previously reported cases of genetically confirmed juvenile/adult-onset VWM since 2001, we attempted to delineate the clinical symptoms, disease evolution, episodic aggravation, associated symptoms, MRI findings and genotypic characteristics of adult VWM. The onset age of neuropsychiatric symptoms was 23.4 ± 10.6years, and the mean follow-up time was 8.1 ± 4.8years. Major clinical symptoms included headache, epilepsy, cognitive decline, cerebellar ataxia, and urinary disturbances. Episodic aggravation was found in 42.9% of the patients in our series. Molecular studies revealed fourteen novel missense mutations. Diffuse abnormal signals characterized by T1-weighted hypointensity and T2-weighted hyperintensity were observed in the supratentorial white matter. The symmetrical leukoencephalopathy must be considered in patients of any age with premature ovarian failure or optic neuropathy. The VWM disease spectrum consists of characteristicimaging findings in combinationwith extremely wide variability in VWM patients.

Therapy Trial Design in Vanishing White Matter: An Expert Consortium Opinion.

Vanishing white matter (VWM) is a leukodystrophy caused by recessive variants in the genes EIF2B1-EIF2B5. It is characterized by chronic neurologic deterioration with superimposed stress-provoked episodes of rapid decline. Disease onset spans from the antenatal period through senescence. Age at onset predicts disease evolution for patients with early onset, whereas disease evolution is unpredictable for later onset; patients with infantile and early childhood onset consistently have severe disease with rapid neurologic decline and often early death, whereas patients with later onset have highly variable disease. VWM is rare, but likely underdiagnosed, particularly in adults. Apart from measures to prevent stressors that could provoke acute deteriorations, only symptomatic care is currently offered. With increased insight into VWM disease mechanisms, opportunities for treatment have emerged. EIF2B1-EIF2B5 encode the 5-subunit eukaryotic initiation factor 2B complex, which is essential for translation of mRNAs into proteins and is a principal regulator of the integrated stress response (ISR). ISR deregulation is central to VWM pathology. Targeting components of the ISR has proven beneficial in mutant VWM mouse models, and several drugs are now in clinical development. However, clinical trials in VWM pose considerable challenges: low numbers of known patients with VWM, unpredictable disease course for patients with onset after early childhood, absence of intermediate biomarkers, and novel first-in-human molecular targets. Given these challenges and considering the critical need to offer therapies, we have formulated recommendations for enhanced diagnosis, drug trial setup, and patient selection, based on our expert evaluation of molecular, laboratory, and clinical data.

Vanishing White Matter Disease Presenting as Acute Febrile Encephalopathy: Case Report

AbstractA 3.5-year-old male child patient with mild developmental delay presented with history of acute onset fever, encephalopathy, and dyskinesia. The patient was investigated for common etiologies and was managed supportively. His neuroimaging was suggestive of vanishing white matter (VWM) disease which was confirmed by clinical exome sequencing. The child had an eventful hospital stay followed by near-total recovery after 4 weeks. The case attempts to sensitize readers about the current perspectives pertaining to VWM disease.

Oligodendrocytes depend on MCL-1 to prevent spontaneous apoptosis and white matter degeneration

Neurologic disorders often disproportionately affect specific brain regions, and different apoptotic mechanisms may contribute to white matter pathology in leukodystrophies or gray matter pathology in poliodystrophies. We previously showed that neural progenitors that generate cerebellar gray matter depend on the anti-apoptotic protein BCL-xL. Conditional deletion of Bcl-xL in these progenitors produces spontaneous apoptosis and cerebellar hypoplasia, while similar conditional deletion of Mcl-1 produces no phenotype. Here we show that, in contrast, postnatal oligodendrocytes depend on MCL-1. We found that brain-wide Mcl-1 deletion caused apoptosis specifically in mature oligodendrocytes while sparing astrocytes and oligodendrocyte precursors, resulting in impaired myelination and progressive white matter degeneration. Disabling apoptosis through co-deletion of Bax or Bak rescued white matter degeneration, implicating the intrinsic apoptotic pathway in Mcl-1-dependence. Bax and Bak co-deletions rescued different aspects of the Mcl-1-deleted phenotype, demonstrating their discrete roles in white matter stability. MCL-1 protein abundance was reduced in eif2b5-mutant mouse model of the leukodystrophy vanishing white matter disease (VWMD), suggesting the potential for MCL-1 deficiency to contribute to clinical neurologic disease. Our data show that oligodendrocytes require MCL-1 to suppress apoptosis, implicate MCL-1 deficiency in white matter pathology, and suggest apoptosis inhibition as a leukodystrophy therapy.

Leukoencephalopathy with vanishing white matter caused by <i>EIF2B5</i> gene mutations: a case report

Leukoencephalopathy with vanishing white matter (VWM disease) is a progressive neurodegenerative disease with a specific magnetic resonance pattern characterized by diffuse lesions to the white matter and cystic degeneration. In this article, we report a case VWM disease in a boy with white matter lesions, in whom early onset and neurological symptoms suggested infantile form of the disease. The diagnosis was confirmed by the detection of biallelic mutations c.1688G>A (p.Arg563Gln) and c.1309G>A (p.Val437Met) in the EIF2B5 gene. The c.1309G>A mutation (p.Val437Met) was detected for the first time; it caused the development of severe disease.

Genomic analysis identify a new EIF2B3 gene variant detected in an uncertain case of CADASIL disease

Vanishing white matter disease (VWM) is an autosomal recessive leukodystrophy caused by mutations genes encoding the translational initiation factor 2B: EIF2B1-EIFB5. It is a heterogeneous neurological disorder with prominent cerebellar ataxia and spasticity in childhood-onset form and behavioural changes, dementia and seizures in adult-onset form (̴15% of cases). We present the case of a 60 years old patient, MTHFR homozygous, presenting white matter lesions and a subcortical vascular encephalopathy being diagnosed.

VANISHING WHITE MATTER DISEASE WITH CENTRAL HYPOMYELINATION

Vanishing white matter disease (VWM) is the most prevalent inherited leucoencephalopathies in children with central hypomyelination. The classical phenotype is characterized by early onset of chronic neurological deterioration, dominated by cerebellar ataxia. The phenotypic variation is extremely wide from antenatal in onset type with early demise to adult in onset with slowly progressive disease. The basic defect is in one of the ve sub-units of eIF2Binitiation factor. Here we report a case of 80 days old male infant with decreased weight gain, stiffness of all four limbs, seizures following head trauma in whom MRI brain identied T2 hyperintensities in white matter of fronto-temporo-parieto-occipital regions and on DWI, it showed abnormal white matter with increased diffusivity reecting the rarefaction and cystic degenerations. Hence diagnosis of VWM disease was established.

Adult-onset vanishing white matter disease with psychiatric manifestation: A case report

Leukodystrophies are genetic neurological disorders characterized by involvement of the white matter of the CNS that may occur at all age. The ovarioleukodystrophies comprise a group of rare leukodystrophies associated with primary or premature ovarian failure.

Leukodystrophy Due to eIF2B Mutations in Adults.

Vanishing white matter disease (VWMD) due to eIF2B mutations is a common leukodystrophy characterised by childhood onset, autosomal recessive inheritance, and progressive clinical course with episodic worsening. There are no reports of genetically confirmed adult patients from India. We describe the phenotype of two adults with genetically confirmed VWMD and typical radiological findings. Both had spastic ataxia and cognitive and behavioural disturbances. Other neurological features included myoclonic jerks and parkinsonism. At the last follow-up (duration: 2-9 years), one patient was wheelchair-bound. VWMD is rare in adults but should be suspected based on radiological findings and confirmed by eIF2B mutation.

The Energy Status of Astrocytes Is the Achilles' Heel of eIF2B-Leukodystrophy.

Translation initiation factor 2B (eIF2B) is a master regulator of global protein synthesis in all cell types. The mild genetic Eif2b5(R132H) mutation causes a slight reduction in eIF2B enzymatic activity which leads to abnormal composition of mitochondrial electron transfer chain complexes and impaired oxidative phosphorylation. Previous work using primary fibroblasts isolated from Eif2b5(R132H/R132H) mice revealed that owing to increased mitochondrial biogenesis they exhibit normal cellular ATP level. In contrast to fibroblasts, here we show that primary astrocytes isolated from Eif2b5(R132H/R132H) mice are unable to compensate for their metabolic impairment and exhibit chronic state of low ATP level regardless of extensive adaptation efforts. Mutant astrocytes are hypersensitive to oxidative stress and to further energy stress. Moreover, they show migration deficit upon exposure to glucose starvation. The mutation in Eif2b5 prompts reactive oxygen species (ROS)-mediated inferior ability to stimulate the AMP-activated protein kinase (AMPK) axis, due to a requirement to increase the mammalian target of rapamycin complex-1 (mTORC1) signalling in order to enable oxidative glycolysis and generation of specific subclass of ROS-regulating proteins, similar to cancer cells. The data disclose the robust impact of eIF2B on metabolic and redox homeostasis programs in astrocytes and point at their hyper-sensitivity to mutated eIF2B. Thereby, it illuminates the central involvement of astrocytes in Vanishing White Matter Disease (VWMD), a genetic neurodegenerative leukodystrophy caused by homozygous hypomorphic mutations in genes encoding any of the 5 subunits of eIF2B.

Sugar phosphate activation of the stress sensor eIF2B

The multi-subunit translation initiation factor eIF2B is a control node for protein synthesis. eIF2B activity is canonically modulated through stress-responsive phosphorylation of its substrate eIF2. The eIF2B regulatory subcomplex is evolutionarily related to sugar-metabolizing enzymes, but the biological relevance of this relationship was unknown. To identify natural ligands that might regulate eIF2B, we conduct unbiased binding- and activity-based screens followed by structural studies. We find that sugar phosphates occupy the ancestral catalytic site in the eIF2Bα subunit, promote eIF2B holoenzyme formation and enhance enzymatic activity towards eIF2. A mutant in the eIF2Bα ligand pocket that causes Vanishing White Matter disease fails to engage and is not stimulated by sugar phosphates. These data underscore the importance of allosteric metabolite modulation for proper eIF2B function. We propose that eIF2B evolved to couple nutrient status via sugar phosphate sensing with the rate of protein synthesis, one of the most energetically costly cellular processes.

Adult-onset vanishing white matter disease presenting as dementia

This study aimed to preliminary examine the effect of DMV stimulation on cognitive function in the elderly with moderate dementia. In the single arm study, 5 participants over 85 years old (% female: 100%) with Alzheimer’s disease completed treatment of DMV stimulation with 15-40 Hz. 15-40 Hz DMV stimulation was provided during the entire day for 4 weeks.

A Vanishing White Matter Disease Case with a Homozygous Point Mutation in the EIF2B2 Gene Assessed by the Whole-Exome Sequencing

A 30-year-old female patient presented with a progressive gait disturbance, who had been previously diagnosed for cataract and ovarian failure. Brain magnetic resonance imaging showed a high signal intensity of white matter in fluid attenuated inversion recovery and low signal intensity in brain volume imaging, suggesting demyelinating leukodystrophy. Genetic analysis confirmed the pathogenic homozygous mutations c.245T>A in the EIF2B2 gene, which is associated with vanishing white matter disease.

Eif2b3 mutants recapitulate phenotypes of vanishing white matter disease and validate novel disease alleles in zebrafish.

Leukodystrophy with vanishing white matter (VWM), also called Childhood Ataxia with Central Nervous System Hypomyelination, is caused by mutations in the subunits of the eukaryotic translation initiation factor, EIF2B1, EIF2B2, EIF2B3, EIF2B4 or EIF2B5. However, little is known regarding the underlying pathogenetic mechanisms, and there is no curative treatment for VWM. In this study, we established the first EIF2B3 animal model for VWM disease in vertebrates by CRISPR mutagenesis of the highly conserved zebrafish ortholog eif2b3. Using CRISPR, we generated two mutant alleles in zebrafish eif2b3, 10- and 16-bp deletions, respectively. The eif2b3 mutants showed defects in myelin development and glial cell differentiation, and increased expression of genes in the induced stress response pathway. Interestingly, we also found ectopic angiogenesis and increased VEGF expression. Ectopic angiogenesis in the eif2b3 mutants was reduced by the administration of VEGF receptor inhibitor SU5416. Using the eif2b3 mutant zebrafish model together with in silico protein modeling analysis, we demonstrated the pathogenicity of 18 reported mutations in EIF2B3, as well as of a novel variant identified in a 19-month-old female patient: c.503T > C (p.Leu168Pro). In summary, our zebrafish mutant model of eif2b3 provides novel insights into VWM pathogenesis and offers rapid functional analysis of human EIF2B3 gene variants.

Mutational analysis of the alpha subunit of eIF2B provides insights into the role of eIF2B bodies in translational control and VWM disease

Eukaryotic initiation factor 2B (eIF2B) serves as a vital control point within protein synthesis and regulates translation initiation in response to cellular stress. Mutations within eIF2B result in the fatal disease, leukoencephalopathy with vanishing white matter (VWM). Previous biochemical studies on VWM mutations have illustrated that changes in the activity of eIF2B poorly correlate with disease severity. This suggests that there may be additional characteristics of eIF2B contributing to VWM pathogenesis. Here, we investigated whether the localization of eIF2B to eIF2B bodies was integral for function and whether this localization could provide insight into the pathogenesis of VWM. We demonstrate that the regulatory subunit, eIF2Bα, is required for the assembly of eIF2B bodies in yeast and that loss of eIF2B bodies correlates with an inability of cells to regulate eIF2B activity. Mutational analysis of eIF2Bα showed that missense mutations that disrupt the regulation of eIF2B similarly disrupt the assembly of eIF2B bodies. In contrast, when eIF2Bα mutations that impact the catalytic activity of eIF2B were analyzed, eIF2B bodies were absent and instead eIF2B localized to small foci, termed microfoci. Fluorescence recovery after photobleaching analysis highlighted that within these microfoci, eIF2 shuttles more slowly indicating that formation of eIF2B bodies correlates with full eIF2B activity. When eIF2Bα VWM mutations were analyzed, a diverse impact on localization was observed, which did not seem to correlate with eIF2B activity. These findings provide key insights into how the eIF2B body assembles and suggest that the body is a fundamental part of the translational regulation via eIF2α phosphorylation.

Vanishing white matter disease expression of truncated EIF2B5 activates induced stress response.

Vanishing white matter disease (VWM) is a severe leukodystrophy of the central nervous system caused by mutations in subunits of the eukaryotic initiation factor 2B complex (eIF2B). Current models only partially recapitulate key disease features, and pathophysiology is poorly understood. Through development and validation of zebrafish (Danio rerio) models of VWM, we demonstrate that zebrafish eif2b mutants phenocopy VWM, including impaired somatic growth, early lethality, effects on myelination, loss of oligodendrocyte precursor cells, increased apoptosis in the CNS, and impaired motor swimming behavior. Expression of human EIF2B2 in the zebrafish eif2b2 mutant rescues lethality and CNS apoptosis, demonstrating conservation of function between zebrafish and human. In the mutants, intron 12 retention leads to expression of a truncated eif2b5 transcript. Expression of the truncated eif2b5 in wild-type larva impairs motor behavior and activates the ISR, suggesting that a feed-forward mechanism in VWM is a significant component of disease pathophysiology.

Profile of Indian Children with Childhood Ataxia and Central Nervous System Hypomyelination/Vanishing White Matter Disease: A Single Center Experience from Southern India.

Background Childhood ataxia with central nervous system hypomyelination (CACH) is a recently described childhood inherited white matter disease, caused by mutations in any of the five genes encoding eukaryotic translation initiation factor ( eIF2B ). Methods Retrospective review of the charts of children with CACH was performed from January 2014 to March 2020 at tertiary care center from Southern India. Diagnosis was based on magnetic resonance imaging (MRI) criteria or genetic testing. Results Total number of children with CACH enrolled were 18. Male/female ratio was 10:8. Mean age of presentation was 37.11 months (range = 6-144 months). Affected siblings were seen in five (28%) cases. All children had spasticity, ataxia, and diffuse white matter changes with similar signal as cerebrospinal fluid on all pulse sequences on MRI brain. Of the 18 children, only nine are alive. Duration of illness among deceased children was 9.6667 months (range = 2-16 months). Waxing and waning of symptoms were seen in seven cases. Genetic analysis of EIF2B gene was performed in five cases, among which three mutations were novel. Conclusion A diagnosis of childhood ataxia with central nervous system hypomyelination should be considered in patients presenting with acute onset neuroregression following infection or trauma with associated neuroimaging showing classical white matter findings.

Saccharomyces cerevisiae ER membrane protein complex subunit 4 (EMC4) plays a crucial role in eIF2B-mediated translation regulation and survival under stress conditions

BackgroundEukaryotic initiation factor 2B (eIF2B) initiates and regulates translation initiation in eukaryotes. eIF2B gene mutations cause leukoencephalopathy called vanishing white matter disease (VWM) in humans and slow growth (Slg−) and general control derepression (Gcd−) phenotypes in Saccharomyces cerevisiae. ResultsTo suppress eIF2B mutations, S. cerevisiae genomic DNA library was constructed in high-copy vector (YEp24) and transformed into eIF2B mutant S. cerevisiae strains. The library was screened for wild-type genes rescuing S. cerevisiae (Slg−) and (Gcd−) phenotypes. A genomic clone, Suppressor-I (Sup-I), rescued S. cerevisiae Slg− and Gcd− phenotypes (gcd7-201 gcn2∆). The YEp24/Sup-I construct contained truncated TAN1, full length EMC4, full length YGL230C, and truncated SAP4 genes. Full length EMC4 (chaperone protein) gene was sub-cloned into pEG (KG) yeast expression vector and overexpressed in gcd7-201 gcn2∆ strain which suppressed the Slg− and Gcd− phenotype. A GST-Emc4 fusion protein of 47 kDa was detected by western blotting using α-GST antibodies. Suppression was specific to gcd7-201 gcn2∆ mutation in eIF2Bβ and Gcd1-502 gcn2∆ in eIF2Bγ subunit. Emc4p overexpression also protected the wild type and mutant (gcd7-201 gcn2∆, GCD7 gcn2∆, and GCD7 GCN2∆) strains from H2O2, ethanol, and caffeine stress. ConclusionsOur results suggest that Emc4p is involved in eIF2B-mediated translational regulation under stress and could provide an amenable tool to understand the eIF2B-mediated defects.

A case report of leukoencephalopathy with vanishing white matter disease

Vanishing white matter disease (VWM) is one of the most prevalent inherited childhood leucoencephalopathies. Childhood ataxia and diffuse central nervous system hypomyelination are the common findings. The disease is characterized by chronic progressive and episodic deterioration with ataxia, spasticity and optic atrophy. VWM is caused by mutation in any of the five genes encoding the subunits of eukaryotic translation initiation factor eIF2B. The disease has an autosomal recessive mode of inheritance. The cause of the disease is unknown. Authors are reporting an 8 year old male child presented with complaint of difficulty while walking since one month and history viral fever was present one month back. MRI revealed bilateral symmetrical periventricular T2 hyperintensities with T1 hypointensities. Perivenular sparing was seen and molecular analysis shown eIF2B4 mutations confirmation of vanishing white matter disease. No specific treatment is available and advised to avoid stress and triggers.

Abstract TMP94: Frequencies of Hereditary Cerebral Small Vessel Diseases Among Patients With Adult-Onset Leukoencephalopathy

Introduction: Recently, various causative genes have been identified in adult-onset white matter disorders. Some of these genes cause cerebral small vessel disease (CSVD). However, the frequency of genetic CSVD is unknown in the group of adult-onset white matter disorders (leukoencephalopathy). The purpose of this study is to clarify the frequency of genetic CSVD in adult-onset leukoencephalopathy patients and to examine their clinical features. Methods: One hundred patients in the Japanese cohort were included. All patients had neurological symptoms/signs and white matter lesions of grade 3/III classified by Fazekas grade on magnetic resonance imaging. Initially, genetic tests for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), high-temperature requirement A serine peptidase 1 (HTRA1)- related CSVD and retinovasculopathy with cerebral leukoencephalopathy (RVCL) were performed by Sanger method. For the remaining samples, we preformed whole exome sequencing. Patients were divided into groups according to the age at onset of neurological signs/symptoms and family history. Results: In 40 of 100 patients with leukoencephalopathy, we identified genetic mutations that cause CSVD: twenty-five patients with CADASIL,10 patients with HTRA1 -related CSVD, 3 patients with pseudoxanthoma elasticum (PXE), 1 patient with RVCL, and 1 patient with a mutation in COL4A1 . More than 85% patients have mutations in NOTCH3 or HTRA1 . In addition, we identified 3 patients with vanishing white matter disease, and 1 patient with X-linked adrenoleukodystrophy. The hereditary CSVDs other than CADASIL or HTRA1 -related CSVD were identified in the groups of age at onset ≤ 40 years-old irrespective of family history or age at onset ≤ 55 years-old with family history. Conclusions: The frequencies of genetic CSVDs were quite high among patients with leukoencephalopathy with neurological signs/symptoms. Although the genetic tests for CADASIL and HTRA1- related CSVD are sufficient for the most patients, we should consider the other genetic diseases especially for the patients with younger age onset of neurological signs/symptoms or positive family history.