Characteristic findings of mitochondrial disorders
- Muscle weakness
- Vision or hearing problems
- Liver or kidney disorder
- Gastrointestinal problems
- Brain problems such as seizures
- Fatigue which may have sudden onset
- Individuals need to have a place to rest and recharge
- Individuals will have good and bad days
- Body’s inability to properly regulate temperature and stay hydrated
- Monitor for temperature extremes
Specific Mitochondrial Syndromes
- Leber hereditary optic neuropathy is a disorder that affects the eye.
- Mitochondrial hearing loss and deafness
- Kearns-Sayre syndrome (KSS) is a condition that affects many parts of the body, especially the eyes.
- Chronic progressive external ophthalmoplegia (CPEO) is a disorder characterized by slowly progressive paralysis of the muscles around the eyes.
- MELAS (Mitochondrial encephalopathy with lactic acidosis and stroke like episodes) primarily affects the brain, nervous system and muscles.
- MERRF (Myolonic epilepsy with ragged red fibers) affects the nervous system and skeletal muscle as well as other body systems.
- NARP: Neurogenic weakness with ataxia
- Leigh syndrome is characterized by progressive loss of mental and movement abilities (psychomotor regression) and typically results in death within a couple of years.
Non-Specific Mitochondrial Disorders
- Overlapping features of the above conditions can occur.
- Individuals with multiple medical symptoms have been found to have deficiencies in the function of their mitochondria do to genetic changes.
Genetics of mitochondrial disorders
- There are approximately 1,200 people in the United States who have a mitochondrial disorder.
- It can be caused by changes in genes that are found on chromosomes and inherited from one or both parents.
- It can be caused by changes in genes that are only found in the mitochondria and are passed on from the mother.
- See the Genetics Home Reference on mitochondrial DNA for more information.
Other possible findings
- Developmental delay
- Mental retardation
- Neuro-psychiatric disturbances
- Atypical cerebral palsy
- Movement disorders
- Autistic features
- Weakness (maybe intermittent)
- Absent reflexes
- Neuropathic pain (pins and needles) and burning
- Dysautonomia (temperature instability and other dysautonomic problems)
- Muscle pain and spasms
- Low muscle tone and loss of muscle coordination
- Exercise intolerance
- May use a wheelchair
- Learning delays
- Autism or autism-like features
- Gastrointestinal problems:
- Pseudo obstruction (the impairment of the intestines in passing food through the intestines.)
- Irritable bowel syndrome
- Dysmotility (slowing down of bowels)
- Unexplained vomiting
- GI reflux
- Kidney disorder
- Cardiac conduction defects
- Hypoglycemia (low blood sugar)
- Liver failure
Eyes and ears:
- Visual loss/blindness
- Ptosis (drooping of the upper eyelid)
- Optic atrophy (deterioration of the optic nerve)
- Hearing loss/deafness
- Retinitis pigmentosis (breakdown and loss of retinal cells)
- Sensitivity to bright lights
- Diabetes and exocrine pancreatic failure
- Inability to make digestive enzymes
- Parathyroid failure (low calcium)
- Short stature
- Failure to gain weight
- Respiratory problems
Increased risk of infection:
- It may take longer to recover from cold or other illnesses
Thyroid or adrenal, autonomic dysfunction