Hereditary motor and sensory neuropathy VIA with optic atrophy disease (HMSN VIA; Charcot–Marie–Tooth disease type 6A; CMT6A) is an autosomal dominant disease caused by monoallelic pathogenic variants in MFN2 [38]. The gene discussed is MFN2; the disease is neuropathy, hereditary motor and sensory, type 6A.