From the WES data, we could exclude mutations in OPA1, OPA3, TMEM126A, WFS1, MFN2, SPG7, RTN4IP1 and AFG3L2 and the common mtDNA mutations associated with LHON at positions 11778/ND4, 3460/ND1 and 14484/ND6 in the index patient. The gene discussed is MFN2; the disease is Leber hereditary optic neuropathy.