DE-NOVO 14484-MITOCHONDRIAL-DNA MUTATION IN MONOZYGOTIC TWINS DISCORDANT FOR LEBERS HEREDITARY OPTIC NEUROPATHY

Monozygotic twin brothers, clinically discordant for Leber's hereditar y optic neuropathy (LHON), had a heteroplasmic point mutation at posit ion 14484 in the mitochondrial DNA that was not detected in their moth er. Moreover, the mutation occurred on the rare European haplogroup X, rather than the haplogroup J commonly associated with the 14484 mutat ion. These data indicate that the 14484 mutation in this family was a new mutation, indicating that it was the de novo occurrence of a commo n, primary LHON mutation.