Leber's Hereditary Optic Neuropathy
1. The first mitochondrial disease to be elucidated at the molecular leave.
2. maternal inheritance - you inherit mitochondria and mtDNA from your mother
3. affects the CNS, including the optic nerves, causing sudden onset blindness in early adulthood due to the death of the optic nerve.
4. In nearly all families, LHON results from SINGLE BASE CHANGES IN THE MITOCHONDRIAL GENES FOR THREE SUBUNITS OF COMPLEX I, resulting in a lowered activity for complex I
5. Patients with lower percentage of mutant mtDNA develop the sudden-onset blindness in early adulthood and other symptoms typical of LHON. Patients with a higher percentage of mutant mtDNA carrying the identical mutation develop dystonia, a severe disease characterized by early onset of generalized movement disorder, impaired speech, and mental retardation.