Friedreich’s ataxia (FA), for example, is caused by defects in frataxin, a mitochondria-localized protein involved in iron homeostasis, while deficiencies in the mitochondria-localized lipid antioxidant enzyme GPX4 can cause Sedaghatian-type spinal metaphyseal dysplasia (1–3). This evidence concerns the gene FXN and Friedreich ataxia.