Walsh & Hoyt: Disorders of Mitochondria

The mitochondrial encephalomyopathies are caused by defects in oxidative phosphorylation in mitochondria. Energy-dependent tissues are most vulnerable. These include muscle, brain, retina, and optic nerve. These diseases may be caused by mutations of either the mitochondrial DNA or nuclear DNA. Disorders of ophthalmologic interest include the Kearns-Sayre syndrome, Lebers hereditary optic neuropathy, the syndrome of myoclonic epilepsy and ragged red fibers (MERRF syndrome), the syndrome of mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS syndrome), and subacute necrotizing encephalomyelopathy (Leighs disease).