Experiments on human fibroblast harbouring the NARP-associated m.8933T > G mutation indicate that complex V deficiency could be rescued by increasing mitochondrial substrate-level phosphorylation through alpha-ketoglutarate/aspartate supplementation, adding useful information to the current knowledge of NARP and MILS pathogenesis [58]. This evidence concerns the gene NPTX2 and maternally-inherited Leigh syndrome.