Study of N-acetylcysteine in the Treatment of Patients With the m.3243A>G Mutation and Low Brain Glutathione Levels

Patients with the m.3243A\>G mitochondrial mutation often have low brain glutathione levels. These low levels can reduce the repair processes in the brain to fix toxic chemicals that result from a mitochondrial disorder. The investigators are aware of a potent anti-oxidant, called N-Acetylcysteine (NAC), that may improve the brain glutathione level when taken in sufficient quantity. In turn, cognitive and motor skill impairment may improve as these toxic levels are reduced. will be studied to investigate the effects on brain glutathione levels, cognitive skills, motor skills, and quality of life.