Adult-onset vanishing white matter in a patient with EIF2B3 variants misdiagnosed as multiple sclerosis.

BACKGROUND: Vanishing white matter (VWM) is an autosomal recessive disorder characterized by childhood ataxia with central hypomyelination. Adult-onset VWM should be considered as a differential diagnosis for suspected cases of multiple sclerosis (MS). METHODS: Targeted region sequencing (TRS) and Sanger sequencing validation were performed to identify and validate the likely pathogenic mutations in a family with VWM. RESULTS: The main clinical manifestations of the proband included decreased vision and sleepiness accompanied by atrophy of the corpus callosum, affected inner rim of the corpus callosum, decreased apparent diffusion coefficient value or persistent hyperintensity-diffusion-weighted imaging, atrophied optic nerve, and no recordable visual evoked potentials. Due to the slow development and atypical VWM image features, MS was initially suspected. After prednisone was administered, the patient's condition did not improve significantly, and other diseases were considered. The TRS and Sanger sequencing identified compound heterozygous mutations of EIF2B3 in the proband; c.965C > G /p.Ala322Gly in exon 8 and c.130G > A/p.Glu44Lys in exon 2 were missense mutations inherited from the mother and father, respectively. The proband's oldest brother had the same compound heterozygous mutations but showed no symptoms. CONCLUSION: This is the first report of adult-onset VWM in a Chinese family. Initially, MS was suspected, and genetic testing confirmed the diagnosis of VWM. This study may further broaden the clinical spectrum of EIF2B3, thus providing a foundation for further research on the pathogenesis and genetic therapy for VWM.

Adult-onset vanishing white matter disease as differential diagnosis of primary progressive multiple sclerosis: a case report.

We report the case of a 42-year-old woman with a slowly progressive cerebellar syndrome. In contrast to a relatively mild clinical presentation, the magnetic resonance imaging (MRI) showed extensive leukencephalopathy with cystic degeneration. Initially primary progressive multiple sclerosis (PPMS) was suspected. Additional diffusion-weighted imaging revealed restricted diffusion in the white matter lesions with a reduced apparent diffusion coefficient. Genetic testing showed vanishing white matter disease (VWM) with c.260C>T EIF2B3 mutation. In conclusion, in cases with relatively mild symptoms and extensive white matter lesions, adult-onset VWM should be considered as differential diagnosis of PPMS and diffusion-weighted imaging may be helpful to identify suspected cases.

Case Report: A Novel EIF2B3 Pathogenic Variant in Central Nervous System Hypomyelination/Vanishing White Matter.

Leukodystrophies are a group of heterogeneous disorders affecting brain myelin. Among those, childhood ataxia with central nervous system hypomyelination/vanishing white matter (CACH/VWM) is one of the more common inherited leukodystrophies. Pathogenic variants in one of the genes encoding five subunits of EIF2B are associated with CACH/VWM. Herein, we presented a case of CACH/VWM who developed ataxia following a minor head injury. Brain magnetic resonance imaging showed extensive white matter signal abnormality. Diagnosis of CACH/VWM was confirmed by the presence of compound heterozygous variants in EIF2B3: the previously known pathogenic variant c c.260C>T (p.Ala87Val) and the novel variant c.673C>T (p.Arg225Trp). Based on the American College of Medical Genetics (ACMG) recommendations, we classified p.Arg225Trp as likely pathogenic. We report a novel variant in a patient with CACH/VWM and highlight the importance of genetic testing in patients with leukodystrophies.

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.

Case of Childhood Ataxia with Central Nervous System Hypomyelination with a Novel Mutation in EIF2B3 gene.

A 4-year-old boy presented with loss of motor milestones following viral fever. On examination, the child had increased tone and exaggerated deep tendon reflexes. Magnetic resonance imaging of the brain showed white matter hyperintensities on T2-weighted images, which revealed partial inversion on fluid-attenuated inversion recovery images. Clinical exome sequencing revealed a novel homozygous mutation c.1270T>G: pCys424Gly in exon 11 of the EIF2B3 gene. This novel mutation is reported in this article along with a literature review.

Endoplasmic reticulum stress intolerance in EIF2B3 mutant oligodendrocytes is modulated by depressed autophagy.

OBJECTIVE: Eukaryotic translation initiation factor 2B (eIF2B) is an essential factor for the initiation of protein synthesis. Mutations in eIF2B encoded by EIF2B1-5 cause a lethal leukoencephalopathy--vanishing white matter disease (VWM). Previous studies have suggested that an improper activated unfolded protein response (UPR) after endoplasmic reticulum stress (ERS) contributed to the pathogenesis of the disease. Autophagy, an important compensatory pathway after ERS, was analyzed in this study. METHODS: To determine the tolerance differences to ERS, cell viability and apoptosis rates were detected in oligodendrocyte cell lines transfected with EIF2B3-c.1037T>C or the wild type. Autophagy flux was measured between groups. Autophagy inducers and inhibitors were used to identify the role of autophagy in the mutant oligodendrocytes. RESULTS: We confirmed that oligodendrocytes with mutant EIF2B3 was less tolerant to ERS than the wild type, with decreased cell viability and increased apoptosis rates. Autophagy flux was depressed in mutant oligodendrocytes under baseline condition and after ERS stimulation. Reduced expression of autophagy related gene (Atg) 3 and Atg 7 were involved in the depression of autophagy flux. The mutant oligodendrocytes pretreated with autophagy inducers showed stable cell viability and decreased apoptosis despite ERS induction, whereas the autophagy inhibitors aggravated cell apoptosis and viability declination. CONCLUSIONS: Oligodendrocytes transfected with mutant EIF2B3 was less tolerant to ERS than the wild type. Depressed autophagy flux was observed in the mutant cells at baseline and after ERS stimulation. Improperly depressed autophagy played a role in the susceptibility to ERS in EIF2B3 mutant oligodendrocytes.

Vanishing white matter disease in French-Canadian patients from Quebec.

BACKGROUND: Vanishing white matter disease is an autosomal recessive leukodystrophy caused by mutations in any of the five genes encoding the subunits of the eukaryotic translation initiation factor 2B. Most of the reported patients are of North American and European ancestry. OBJECTIVE: The objective of the study was to review the clinical, radiological, and molecular characteristics of vanishing white matter disease in a cohort of French-Canadian patients. METHODS: Between 2004 and March 2012, five French-Canadian (non-Cree) patients from Quebec were clinically and genetically diagnosed with vanishing white matter disease within three Montreal Neurogenetics and Leukodystrophy clinics. Their clinical presentation and evolution, demographic characteristics, genetic mutations, and imaging were reviewed and compared with what is known in the literature. RESULTS: Sequencing of the exons and intronic boundaries of the EIF2B1-5 genes revealed a rare 260C>T (A87V) missense mutation in EIF2B3 in two homozygous patients and one compound heterozygous patient. This mutation was previously reported in only one patient in the literature. The carrier frequency is unknown. Also, three of five Quebec patients had an extremely rare vanishing white matter disease presentation of migraines with transient neurological abnormalities. CONCLUSION: The 260C>T (A87V) mutation in exon 3 of the EIF2B3 gene is likely a founder mutation for vanishing white matter disease in Quebec. Transient hemiparesthesia and hemiparesis episodes accompanied by headaches as presenting abnormalities of vanishing white matter disease are usually rare but seemed to be more frequent among the French-Canadian Quebec patients. They seemed to be preceded by periods of stress.