MT-ND1 and Leber hereditary optic neuropathy: However, variant m.3548T > C was found in patient Le1263, which is located in the mutational hotspot (MT-ND1 gene) for Chinese patients with LHON but lacking three known primary mutations [15] and was also reported in another LHON patient [25], whether m.3548T > C had a synergistic effect with m.10680G > A to influence disease expression in Le1263 was not clear, as we lacked necessary clinical information and this patient had no self-reported family history of disease.