Certain neuropathies, for example, are caused by mutations in Opa1 (autosomal dominant optic atrophy, ADOA) and Mfn2 (Charcot-Marie-Tooth disease type 2A, CMT2A), where patient cells have clear mitochondrial morphology imbalance and dysfunction. The gene discussed is OPA1; the disease is autosomal dominant optic atrophy.