MFN2 and peripheral neuropathy: In addition to peripheral neuropathy, patients with MFN2 variants can sometimes also present with additional phenotypes, including optical atrophy (Leonardi et al., 2015), sensorineural hearing loss (Chung et al., 2006), cerebellar ataxia (Sharma et al., 2021b) and multiple systemic lipomatosis (Capel et al., 2018), to name a few.