ABSTRACT
Mitochondrial encephalomyelopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome was first defined as such by SG. Pavlakis and colleagues in 1984, though patients have doubtless been reported earlier. The common mutation leads to impaired mitochondrial translation that results in increased synthesis of mitochondrial protein. A variety of supportive measures is helpful in this disorder, as in other mitochondrial diseases. The disease is inherited in a maternal pattern, and the gene is on the mitochondrial genome. Cybrids containing more than 95 percent mutant DNA had decreased rates of synthesis and steady-state levels of mitochondrial proteins leading to respiratory chain deficiency. The A3243G mutations lead to impaired and translation and protein synthesis, resulting in impaired mitochondrial energy production. Patients with the MELAS syndrome have been found to have marked deficiency in the activity of complex I of the respiratory chain.
