Leber's hereditary optic neuropathy (LHON) is a maternally inherited blinding disease due to three most frequent mitochondrial DNA (mtDNA) point mutations (11778/ND4, 3460/ND1 and 14484/ND6), which affect complex I subunit genes [1]. Here, MT-ND4 is linked to Leber hereditary optic neuropathy.