Mitochondrial diseases are chronic (long-term), genetic, often inherited disorders that occur when mitochondria fail to produce enough energy for the body to function properly. (Inherited means the disorder was passed on from parents to children.) Mitochondrial diseases can be present at birth, but can also occur at any age.
Mitochondrial diseases can affect almost any part of the body, including the cells of the brain, nerves, muscles, kidneys, heart, liver, eyes, ears or pancreas.