obesity, diabetes and hypertension. A T>C mutation at position 10,663 in the mitochondrial gene MT-ND4L is known to cause Leber's Hereditary Optic Neuropathy (LHON). This mutation results in the replacement of the amino acid valine with alanine at position 65 of the protein ND4L, disrupting function of Complex I in the electron transport chain. It is unknown how this mutation leads to the loss of vision in LHON patients, but it may interrupt ATP production due to the impaired activity of Complex I. Mutations in other genes encoding subunits of Complex I, including MT-ND1, MT-ND2, MT-ND4, MT-ND5, and MT-ND6 are also known to cause LHON. References Further reading External links Mass spectrometry characterization of MT-ND4L at COPaKB Proteins Human mitochondrial genes