[Molecular genetics of disorders of the mitochondrial respiratory chain]

Mitochondria have a key role in cell metabolism, being the major site of ATP production via oxidative phosphorylation. This system consists of five multiprotein complexes, whose individuals subunits are encoded either by the mitochondrial or by the nuclear genome. Respiratory chain enzyme deficiencies result in devastating, usually multisystem, disorders. Recently, many underlying mutations in mitochondrial and nuclear genes have been described at a brisk pace as a result of the advances in the knowledge of molecular genetics.