Characterization of Ataxia-linked MFN2 Variants Reveals a Lipid Droplet/Mitochondrial Axis Driving Ferroptosis

The study examined pathogenic variants of the Mitofusin 2 (MFN2) protein that cause cerebellar ataxia. While most MFN2 variants cause peripheral neuropathy Charcot-Marie-Tooth Type 2A, a smaller subset affects the central nervous system. Research revealed that MFN2 variants linked to ataxia increase cell susceptibility to ferroptosis, a type of programmed cell death. The mechanism involves increased import of fatty acids from lipid droplets into mitochondria, altering cellular lipid composition and contributing to lipid peroxidation. Since ferroptosis is associated with other ataxias such as Friedreich's ataxia, researchers propose that increased ferroptosis sensitivity explains the specific phenotype of MFN2-related ataxia.