[Mutations of the mitochondria genome. Diagnosis and pathogenetic significance].

The mitochondrial respiratory chain, which consists of five enzyme complexes, plays a central part in cellular energy metabolism. Thirteen of the protein sub-units are encoded by the mitochondrial genome, a circular DNA molecule of about 16,500 base pairs. Knowledge of the mitochondrial genome and alterations to it is essential to reveal functional defects of the respiratory chain. Point mutations, deletions and duplications of this DNA are associated with a growing number of diseases, whose clinical presentations vary quite widely.