In any case, this mitochondrial adaptive response could maintain unaffected mutation carriers until compensatory mechanisms are overcome, explaining the incomplete penetrance of LHON and the rapid visual impairment observed in the disease.23,24 No mitophagy clusters or protein aggregates were observed, conversely to what was disclosed in Opa1+/− mice. Here, OPA1 is linked to Leber hereditary optic neuropathy.