Mutant Mid51(R169W), which is located in the Mid51 oligomerization domain, was found to be a potential candidate genetic variant for Parkinson’s disease (Lubbe et al., 2020Preprint), while Mid51(Y240N), located in its Drp1-binding domain, was linked to dominant optic atrophy (Charif et al., 2021). This evidence concerns the gene MIEF1 and autosomal dominant optic atrophy.