Tissue distribution of the ND4/11778 mutation in heteroplasmic lineages with Leber hereditary optic neuropathy

Leber hereditary optic neuropathy (LHON) is a maternally inherited eye disease most commonly caused by mitochondrial DNA (mtDNA) point mutation at position 11778, 3460, or 14484. Approximately 14% of families show heteroplasmy for the pathogenic mutations but little is known about the mutational burden in different tissues of these heteroplasmic individuals. Consequently, estimating the risks of visual loss is difficult. This study presents quantitative mutation analyses of tissues representing all embryonal layers in two families heteroplasmic for the 11778 mutation. These analyses show that a high amount of mutated mtDNA in leukocytes is correlated with a high proportion of mutated mtDNA in other tissues.