Infantile-Onset Vanishing White Matter Disease in an Azerbaijani Infant With a Homozygous EIF2B5 p.(Arg195His) Variant.

An eight-month-old Azerbaijani male infant, born to consanguineous (first-cousin) parents, presented with developmental regression and daily seizures following a febrile illness. He achieved head control at six months (delayed). During the same month, a rotavirus infection (fever, vomiting, and diarrhea) precipitated focal and generalized seizures. Neurological examination at eight months demonstrated severe hypotonia, hyperreflexia, and markedly reduced voluntary movements, with preserved visual and auditory responses. Brain MRI showed diffuse supra- and infratentorial white matter T1 hypointensity and marked T2 hyperintensity, with loss of subcortical U-fibers and deep white matter fluid-attenuated inversion recovery hypointensity consistent with rarefaction/degeneration, while the basal ganglia and cerebral cortex were relatively spared, an imaging pattern highly suggestive of advanced vanishing white matter (VWM) disease. Genetic testing identified a homozygous EIF2B5 c.584G>A (p.Arg195His) variant, supporting the diagnosis. This case illustrates subacute infantile VWM with stressor-related neurologic deterioration, hypotonia, and refractory seizures, underscoring the value of early molecular diagnosis in infants with suspected leukodystrophy.