A novel missense variant in EIF2B5 identified in a consanguineous Iranian family with vanishing white matter disease and a brief review of the literature.

Abstract

Vanishing of white matter (VWM) is a hereditary heterogeneous brain disorder that most often affects children. However, the onset of the disease varies from childhood to adulthood. VWM is caused by mutations in one of the five genes encoding subunits of the eukaryotic initiation factor eIF2B. In the current study, we aimed to determine the genetic cause of VWM in a large consanguineous Iranian family with three affected members. Next-generation sequencing was conducted on the proband to determine the underlying cause of VWM. The identified variant was validated by PCR-Sanger sequencing in the patient and was also segregated in his parents and two other affected members of the pedigree. The potential functional effects of this mutation within EIF2B5 were predicted by in silico analysis. We have also reviewed all EIF2B5 disease-causing variants and available clinical features of each patient reported in HGMD Professional 2022.2. A novel homozygous variant c.746T>G [p.Ile249Ser] was detected in EIF2B5 which was co-segregated with the disease in all affected family members in an autosomal recessive manner. All employed in silico prediction tools and 3D structure analysis for the novel mutation also supported the pathogenicity of this variant. Our study not only expanded the spectrum of the pathogenic variants in EIF2B5 but also presented a literature review on EIF2B5-related conditions that provide a comprehensive picture of the genetic nature of this gene and phenotypic variability in patients.