Question: What is (are) Leber hereditary optic neuropathy ?
Answer: Leber hereditary optic neuropathy (LHON) is an inherited form of vision loss. Although this condition usually begins in a person's teens or twenties, rare cases may appear in early childhood or later in adulthood. For unknown reasons, males are affected much more often than females. This condition is caused by mutations in the MT-ND1, MT-ND4, MT-ND4L, and MT-ND6 genes.
Source: GARD