The molecular biological mechanism of mitochondrial diseases

Mitochondrial diseases are a group of rare disorders due to defects of energy metabolism in mitochondria.The clinical phenotype of mitochondrial diseases ranges from a single structural defect in tissues or no symptoms to multisystemic lesions or even death in early ages.Therefore,this type of diseases are often clinically misdiagnosed or even delayed for treatment.Biologically,structure and function of mitochondria are under the dual control of the mitochondrial genome(mtDNA) and the nuclear genome(nDNA).Due to the fact that most of the enzymes and protein factors of mitochondria are encoded by nDNA,primary mitochondrial diseases are mainly caused by mutations in the nuclear genome and thus are of Mendelian inherited disorders,while others caused by mutations in mtDNA are maternally inherited.The molecular pathogenesis and clinical phenotype vary with mutations in nDNA or mtDNA.This review describes the inheritance,classification and molecular biological mechanisms of mitochondrial diseases.