Mutations in some MICOS components have been reported in humans, including MIC13/QIL1 [135,136,137], causing a severe form of infantile hepato-encephalopathy; MIC26/APOO [138], associated with an X-linked mitochondrial myopathy with cognitive impairment; and MIC60, linked to Parkinsonism [139]. Here, APOO is linked to Cognitive impairment.