Pathogenic variants in the MFN2 (MIM*608507) cause three overlapping phenotypes: Charcot–Marie–Tooth neuropathy type 2A2A (CMT2A2A, MIM#609260), Charcot–Marie–Tooth neuropathy type 2A2B (CMT2A2B, MIM#617087), and hereditary motor and sensory neuropathy VIA with optic atrophy disease (HMSN VIA, MIM#601152). The gene discussed is MFN2; the disease is neuropathy, hereditary motor and sensory, type 6A.