Vanishing white matter disease with different faces

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.

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.

A (dis)integrated stress response: Genetic diseases of eIF2α regulators

The integrated stress response (ISR) is a conserved mechanism by which eukaryotic cells remodel gene expression to adapt to intrinsic and extrinsic stressors rapidly and reversibly. The ISR is initiated when stress-activated protein kinases phosphorylate the major translation initiation factor eukaryotic translation initiation factor 2ɑ (eIF2ɑ), which globally suppresses translation initiation activity and permits the selective translation of stress-induced genes including important transcription factors such as activating transcription factor 4 (ATF4). Translationally repressed messenger RNAs (mRNAs) and noncoding RNAs assemble into cytoplasmic RNA-protein granules and polyadenylated RNAs are concomitantly stabilized. Thus, regulated changes in mRNA translation, stability, and localization to RNA-protein granules contribute to the reprogramming of gene expression that defines the ISR. We discuss fundamental mechanisms of RNA regulation during the ISR and provide an overview of a growing class of genetic disorders associated with mutant alleles of key translation factors in the ISR pathway. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease Translation > Translation Regulation RNA in Disease and Development > RNA in Development.

Identification of a Missense Variant in the EIF2B3 Gene Causing Vanishing White Matter Disease with Antenatal-Onset but Mild Symptoms and Long-Term Survival

Vanishing white matter disease (VWM) is a rare autosomal recessive leukodystrophy caused by a mutation in any of the five gene encoding subunits of the translation initiation factors eIF2B1 to eIF2B5. Whole-exome sequencing was performed on a 7-year-old boy with prenatal symptoms, including intrauterine-growth retardation, decreased movements, and oligohydramnios as well as mild intellectual disability, optic atrophy, macrocephaly, mild ataxia, and white matter lesions after birth. Analysis of WES data revealed a homozygous missense variant, c.C590T (p.Thr197Met) in the EIF2B3 gene (NM_0203650). The candidate variant was confirmed by Sanger sequencing and found to co-segregate with disease in family members. Pathogenicity analysis, 3D protein modeling, and stability assessment showed the deleterious effects of this nucleotide change. Previous studies suggest a direct relationship between the onset of symptoms and the progression rate and severity of the disease. All described cases of EIF2B deficiency with antenatal-onset led prenatal death; if they were born, they experienced clinical exacerbation, seizure, severe encephalopathy, and consequent infantile death (< 1 year). The patient of this study had never had seizure, which could be a potential explanation for the observed mild clinical picture, chronic state, and long-term survival until the age of seven. This study reported the first VWM due to EIF2B gene deficiency with antenatal-onset but mild symptoms and long-term survival. The result of this study showed that stressor factors, particularly seizure, could have a substantial role in poor prognosis and early neonatal death.

CT and MRI findings in infantile vanishing white matter

Infantile vanishing white matter disease is an uncommon cause of developmental delay and seizures in children. Presented here is a case of vanishing white matter disease diagnosed at 6 months of age. Imaging findings demonstrated widespread white matter abnormalities throughout the supratentorial and infratentorial brain. The diagnosis of infantile vanishing white matter disease was confirmed via molecular analysis which revealed a rare mutation in the gene responsible for this disorder.