Mild Leber hereditary optic neuropathy (LHON) in a Western European family due to the rare Asian m.14502T>C variant in the MT-ND6 gene

The rare Asian m.14502T>C variant in the MT-ND6 gene was linked to a mild LHON phenotype in a Western European family. Penetrance in this family was likely triggered by alcohol and tobacco abuse. A full mtDNA sequencing is warranted in the case of high clinical suspicion of LHON when mutation analysis for the three common pathogenic variants is negative.