Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Leber hereditary optic neuropathy with dystonia ?
    ### Response:
    Leber hereditary optic neuropathy (LHON) with dystonia is a very rare variant of LHON where an individual has LHON associated with dystonia, which involves involuntary muscle contractions, tremors, and other unctrolled movements. It is caused by mutations in one of three mitochondrial genes: MT-ND1, MT-ND3, MT-ND4, and MT-ND6.
    