[Leber's optic nerve atrophy; a mitochondrial hereditary disease].

Leber hereditary optic neuropathy (LHON) is a heritable disorder, clinically characterized by rapidly progressive loss of central vision due to severe bilateral optic atrophy. The disease predominantly occurs in men. The clinical picture shows marked interpersonal variation. Recently it has been established that LHON is associated with at least three specific mutations in the mitochondrial DNA, which explains the non-Mendelian, strictly maternal inheritance. The presence of different mutations implies that there is not only clinical but also genetical heterogeneity. Since all matrilinear family members carry the mtDNA mutation involved, but only 30-50% of males and 5-15% of the females develop LHON, other etiological factors, hereditary or exogenous, remain to be discovered. Identification of these factors is of major importance to understand the pathogenesis and to explore the possibilities for therapy and prevention of LHON.