Author Description

The text provides an interesting introduction of the field of mitochondrial biology and mitochondria related disorders. It explains in detail many of the concepts related mitochondrial genome variation and mutations and their effect on human health and disease. The authors have incorporated most of the information from their original laboratory research and from many other sources. Mitochondria are double membrane organelles present in the cytosol of eukaryotic cells. The main function of mitochondria is to produce energy in the form of ATP by utilizing oxygen and the byproducts of the oxidation ofnutrients. The phenomenon of oxidative phosphorylation (OXPHOS) is carried out by five multi-subunit enzyme complexes located in the inner mitochondrial membrane. Mitochondrial encephalomyopathies are a heterogeneous group of clinicaldisorders caused by defects in mitochondrial respiratory chain. The incidence of such disorders is about 1:5000 and mostly occurring in early years after birth. Organs such as the brain, heart and skeletal muscle are highly energy dependent and thus vulnerable to defects in energy metabolism. Mitochondrial dysfunction is common cause of neuromuscular disorders inpediatric patients. The genetic cause of biochemical defect can be mutations in either mitochondrial DNA (mtDNA) or nuclear DNA. A number of mtDNA variants had been associated with the disease. It has been suggested that dysfunction of electron transport chain (ETC) results in increased levels of reactive oxygen species (ROS), which in turn plays an important role in the pathogenic mechanism of mitochondrial encephalomyopathies. Secondly, the mechanism of free radical production bycomplex I deficiency is ill defined, and is of significant contemporary interest. Mitochondria have been found to play a leading role in triggering and mediating the apoptotic process. A defective oxidative phosphorylation (OXPHOS) causes changes in cellular ROS, antioxidant defenses and declined ATP pool, th