The NDUFV1 gene is located on chromosome 11, and there were five clinical categories linked to mitochondrial complex I deficiency (MCID): Leigh syndrome, severe infantile lactic acidosis, newborn cardiomyopathy, progressive leukoencephalopathy, and an unspecified group of other encephalomyopathies [3]. Here, NDUFV1 is linked to mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria.