[Mitochondrial and metabolic myopathies]

Mitochondrial and metabolic myopathies constitute a group of disorders characterised by abnormal muscular metabolism of energy. Most of these disorders are genetically transmitted. Recent progress in the field has led to spectacular advances in their classification and the understanding of the mechanisms involved, particularly in mitochondrail myopathies. Diagnosis can be made et any age; the patient can present manifestations that can be misleading for the clinician. Lipid myopathies and glycogenoses usually present as a myopathic syndrome associated with cramps, spasm and myalgia, with fatigue on effort. Acute episodes of rhabdomyolysis on effort can occur, with an attendant risk of renal failure. Mitochondrial myopathies have multi-organ manifestations and muscular involvement is not always at the forefront. Although diagnosis may be suggested by clinical factors, it should be confirmed by teams and laboratories that specialize in muscular disorders.