Medical Genetics Program of Southwestern Ontario

General Symptoms


Mitochondria are essential organelles. Diseases of the mitochondria affect many organs and organ systems in the body. Click on a part of the body to see the common symptoms of mitochondrial disease associated with that organ.


Mitochondrial diseases are extremely rare conditions with prevalence being approximately 12 in 100 000 people. Mitochondria are organelles found in nearly all body cells. Therefore disorders of mitochondria are typically multisystemic, meaning they affect many organs and areas of the body.

Mitochondria are of course the energy powerhouses of the cell. A disease of these organelles disrupts their ability to make energy for the cell. This lack of energy to areas that demand it makes cells and eventually organs dysfunctional. This energy deficit can be considered the root cause of the symptoms observed in mitochondrial disease.





Dot Meaning “without coordination”
Dot Uncoordinated movements of the arms and legs


Dot A loss in intellectual ability

Migraine headaches


Dot Twitching and jerking caused by sudden contraction of muscles

Peripheral neuropathy

Dot Damage or disease to nerves of the peripheral nervous system
Dot Numbness or tingling sensations in the extremities


Sensorineural hearing loss

Dot Disease or damage of the nerve in the inner ear
Dot May cause complete deafness in one or both ears


Dot Lack of oxygenated blood to the brain which may lead to paralysis, speech and vision problems, pain and other symptoms




External ophthalmoplegia/ophthalmoperesis

Dot Paralysis/weakness of muscles in and around the eyes causing restricted movement of the eyes and appearance of drooping eyelids (ptosis)

Optic neuropathy

Dot Damage to the optic nerve which connects photoreceptor cells to the brain, causing partial or complete blindness

Retinitis Pigmentosa – a group of diseases of the eye characterized by

Dot Swelling of cells in the retina
Dot Vision loss in the night
Dot Peripheral vision loss
Dot Central vision loss


Digestive Tract

Digestive Tract

Dot Dysmotility (pseudo-obstruction)

Dot A group of disorders of the digestive tract caused by improper functioning of muscles that help move food down the tract
Dot This causes various symptoms of the digestive system, often caused by bacterial infections


Dot Hepatopathy

Dot Various forms of liver disease including jaundice, which causes a yellowish discolouration of the skin as a result of an excess chemical called bilirubin


Dot Diabetes mellitus



Exercise intolerance and fatigue


Dot Skeletal muscles that move our bodies require a lot of energy
Dot An energy deficit caused by a mitochondrial causes extreme weakness and constant fatigue
Dot Extreme muscle weakness also means physical activity becomes nearly impossible to tolerate


Dot A disease of muscle fibre, caused by insufficient energy supply to muscle cells





Dot A disease of the heart muscle which may lead to heart failure

Conduction disorder

Dot Abnormalities in the conduction system that controls heartbeat