A recent study reported mutations in SLC25A46 in patients with optic atrophy, axonal Charcot–Marie–Tooth disease (CMT), and cerebellar atrophy (Abrams et al, 2015), and in a patient with an optic atrophy spectrum disorder (Nguyen et al, 2016), but neither study elucidated its molecular function. The gene discussed is SLC25A46; the disease is Leber hereditary optic neuropathy.