Mitochondrial encephalomyopathies encompass a group of disorders that haveimpaired oxidative metabolism in skeletal muscles and central nervous system. As the field of mitochondrialmedicine takes shape and physicians in all specialties become increasingly aware of respiratory chainor oxidative phosphorylation (OXPHOS) related disorders, their prevalence remains largely unknown. Theunique features of the mitochondrial genome and the dual control over this important cellular apparatusmakes the clinical presentation variable and diagnosis difficult. There is a confounding variation inphenotype and genotype, and the natural history of the disorders in individual patients is not accuratelypredictable. Only recently have things begun to fall into place and some phenotypes defined. Diagnosisrequires a complex battery of clinical studies coupled with diagnostic findings on muscle biopsy (abnormalstructure, histochemistry, or enzyme studies) or DNA testing. However, a reasonably confident diagnosiscan be made by viewing the clinical presentation in the light of family history and some basic, routinelyavailable laboratory investigations. This review tries to give a brief account of mitochondrial structure,function and genetics, and clinical presentation, evaluation, and treatment in suspected cases of mitochondrialencephalomyopathies.

Keywords: DNA, Mitochondrial - physiology, Electron Transport, Mitochondria - physiology, Mitochondrial Encephalomyopathies - therapy, Oxidative Phosphorylation