A recent study identified mutations in SLC25A46 in four families with optic atrophy, axonal CMT, and cerebellar atrophy (Abrams et al, 2015), and an additional patient was recently reported with an optic atrophy spectrum disorder (Nguyen et al, 2016), indicating that the neurological phenotypes produced by mutations in this gene are clinically heterogeneous. The gene discussed is SLC25A46; the disease is optic atrophy.