Dominant optic atrophy

Dominant optic atrophy [13, 14] The most prevalent hereditary optic atrophy resulting in a progressive loss of visual acuity, centro-cecal scotoma and bilateral temporal atrophy of the optic nerve. It has been ascribed to mutations in the OPA1 gene encoding a dynamin-related protein localized to mitochondria. Anomalies of mitochondrial integrity and distribution are suspected to result from impairment of protein function. 

Autosomal dominant optic atrophy is an inherited optic neuropathy with variable penetrance and expressivity. Other genetic and environmental factors are postulated to contribute to more marked visual loss in some affected individuals. In an atypical case of ethambutol toxicity, with progressive profound loss of vision despite drug withdrawal, a diagnosis of autosomal dominant optic atrophy was made when the proband s sons presented with mild visual disturbances and color vision defects, confirmed by electrophysiology and OPAl gene mutational analysis [13 ]. 

Genetic predisposition - Emb-induced optic neuropathy occms in patients with mutations in a related fusion gene, OPAl, which is responsible for autosomal dominant optic atrophy [59 ]. 

Abnormalities suggestive of deranged cyanide emd vitamin Bi2 metabolism have been demonstrated in Leber s disease (hereditary optic atrophy) and in dominantly inherited optic atrophy, and consist of significant elevations of pleisma cyanocobalamin [56]. Similar changes have been reported in sporadic cases of bilateral optic atrophy occurring in Europeans, and in cases of so-called tobacco amblyopia. 

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