["To report the clinical, genetic, and molecular characterization of two Chinese families with Leber's hereditary optic neuropathy (LHON).", 'Ophthalmological examinations showed that only probands in two families exhibited visual loss at the age of 10 and 17 years respectively. The entire mitochondrial genome of two probands was PCR amplified in 24 overlapping fragments using sets of oligonucleotide primers.', 'Mutational analysis of mitochondrial DNA (mtDNA) in these pedigrees revealed the absence of three common LHON associated G11778A, G3460A and T144484 mutations but the presence of homoplastic LHON associated ND4 G11696A mutation, which was present in one out of 167 Chinese healthy controls.'] Is [ Leber 's hereditary optic neuropathy associated with the mitochondrial G11696A mutation in two Chinese families ]?