EIF2B5 and leukoencephalopathy with vanishing white matter: VWM is caused by biallelic loss-of-function variants in any of the five genes (EIF2B1-5) that encodes the five subunits (alpha-epsilon) of the eukaryotic translation initiation factor 2B (eIF2B), a guanine nucleotide exchange factor that plays a crucial role in regulating protein synthesis (Leegwater et al., 2001).