Cystic Leucoencephalopathy in NDUFV1 Mutation.

Complex I deficiency is one of the most common mitochondrial respiratory chain defect. This deficiency of oxidative phosphorylation results from mutation in nuclear and mitochondrial DNA. Mutations in NDUFV1 (Flavin binding subunit of Respiratory complex 1) results in neurological manifestations including Leigh syndrome and leucoencephalopathy. The authors report a one-year-old boy with history of regression of motor milestones following a trivial fall from the bed. His magnetic resonance imaging revealed diffuse, cystic leucoencephalopathy involving corpus callosum and periventricular white matter. Clinical features and radiological findings may resemble those of vanishing white matter disease. Next generation sequencing revealed likely compound heterozygous missense pathogenic variant in exon 8 of NDUFV1 gene [c.1156C > C/T (p.Arg386Cys)] and possibly novel splice site variation in intron 2 of NDUFV1 gene (c.155 + 1G > G/A). NDUFV1 related leucoencephalopathy must be considered among those presenting with sudden onset of motor regression with neuroimaging correlate of diffuse cystic leucodystrophy.