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 in Children: An Unusual Association, a Novel Mutation, and a Literature Review

Vanishing white matter (VWM) disease is an autosomal recessive disorder caused by mutations in the gene EIF2B encoding the subunits 1-5 of eukaryotic initiation factor 2B. Although rare, with a reported prevalence of 1:80,000 (0.001%), it was considered as one of the most common leukodystrophies. However, the worldwide incidence and prevalence of this disease are not clear. In Bahrain, of 21 patients who were diagnosed with leukodystrophy, two patients were found to have VWM disease accounting for 9.5%. Vaccinations and infections were the trigger factors for this disease to manifest. Rapid neurological deterioration, loss of developmental milestones, and seizure disorders are the main presentations in both patients. Magnetic resonance imaging (MRI) showed the classical radiological changes of demyelination and leukodystrophy. Patient 1 had associated ulcerative colitis, a finding that was not reported before. Patient 1's condition progressed to a vegetative stage, while patient 2 passed away, reflecting the poor disease outcome. In patient 2, a novel homozygous missense mutation was found in the EIF2B3 gene (c.25G>A, p.Ala9Thr). In this report, we present in detail the prevalence of VWM disease among cases with leukodystrophy, patients' characteristics, clinical presentations, radiological findings, associated diseases, genetic results, and clinical outcomes in the main tertiary hospital in Bahrain between 1998 and 2024. Moreover, we conducted a thorough literature review on this rare condition.

A Novel Pathogenic Mutation in WNK1 Gene Causing HSAN Type II in Three Siblings

Hereditary sensory and autonomic neuropathy (HSAN) is a rare genetic disorder that primarily affects the peripheral nervous system, leading to a progressive loss of the ability to perceive pain, temperature, and touch. This condition can result in severe complications, including injuries and infections due to the inability to feel pain. HSAN is classified into nine types, with types I and VII exhibiting autosomal dominant inheritance, while the others follow an autosomal recessive pattern. In this study, we examined three affected brothers of Turkish Azeri descent, aged 20, 23, and 25 years. They presented symptoms such as a lack of temperature and pain sensation, frequent wounds and infections, self-harm, and hyperkeratosis. To identify the genetic cause of their condition, whole-exome sequencing (WES) was performed, followed by Sanger sequencing to confirm the findings. The results revealed a homozygous likely pathogenic nonsense mutation, c.2971C > T (p.Arg991Ter), in exon 9 of the WNK1 gene. This mutation results in the truncation of three isoforms of the WNK1 protein, which are essential for pain perception. This discovery enhances our understanding of HSAN and highlights the importance of genetic testing for accurate diagnosis and future screening.

Overview of Neuro-Ophthalmic Findings in Leukodystrophies

Background: Leukodystrophies are a group of rare genetic diseases that primarily affect the white matter of the central nervous system. The broad spectrum of metabolic and pathological causes leads to manifestations at any age, most often in childhood and adolescence, and a variety of symptoms. Leukodystrophies are usually progressive, resulting in severe disabilities and premature death. Progressive visual impairment is a common symptom. Currently, no overview of the manifold neuro-ophthalmologic manifestations and visual impact of leukodystrophies exists. Methods: Data from 217 patients in the Hamburg leukodystrophy cohort were analyzed retrospectively for neuro-ophthalmologic manifestations, age of disease onset, and magnetic resonance imaging, visual evoked potential, and optical coherence tomography findings and were compared with data from the literature. Results: In total, 68% of the patients suffered from neuro-ophthalmologic symptoms, such as optic atrophy, visual neglect, strabismus, and nystagmus. Depending on the type of leukodystrophy, neuro-ophthalmologic symptoms occurred early or late during the course of the disease. Magnetic resonance imaging scans revealed pathologic alterations in the visual tract that were temporally correlated with symptoms. Conclusions: The first optical coherence tomography findings in Krabbe disease and metachromatic leukodystrophy allow retinal assessments. Comprehensive literature research supports the results of this first overview of neuro-ophthalmologic findings in leukodystrophies.

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.