What Is the Life Expectancy of People With Mitochondrial Disease?

To date, there has been limited research about the “end-of-life” phase and reasons for death in people with mitochondrial diseases. Although clinical symptoms associated with particular syndromes may indicate the cause of death, it remains difficult to offer a precise prognosis.

Many mitochondrial diseases manifest in childhood. Others emerge later in life. Your age determines the severity of symptoms at the time of onset of the condition and the number of organ systems involved. 

Some of the most severely affected children do not survive their adolescence, and many adults experience their formerly productive lifestyle deteriorate into disability. People who present with the condition neonatally have a lower life expectancy. Comorbidities may sometimes limit life expectancy even with appropriate treatments.

Mitochondrial disease symptoms vary depending on which organ or organ systems are affected. Among them, possible early signs and symptoms include:

• Developmental delays
• Reduced growth
• Fatigue
• Migraine
• Muscle weakness
• Muscle pain
• Cardiomyopathy
• Liver failure
• Blindness
• Optic atrophy (degeneration of the optic nerve)
• Hearing loss
• Diabetes
• Seizures

Clusters of signs and symptoms often emerge, indicating the presence of this rare syndrome.

The involvement of multiple organ systems in three or more areas commonly indicates mitochondrial disease. 

Because mitochondria are found in 90% of our cells, they can affect many organs, including the brain and muscles. The brain, heart, liver, skeletal muscles, kidney, endocrine, and respiratory systems are generally the most affected. 

Signs and symptoms of mitochondrial dysfunction depending on the affected organ system are as follows:

• Neurological
  • Difficulty paying attention
  • Seizures
  • Headaches
  • Loss of control of body movements
  • Sensitivity to noise, lights, and smells
  • Developmental delays
  • Learning disorders
  • Dementia
  • Nerve pain
  • Migraine
  • Stroke
• Ocular
  • Night blindness
  • Decrease in visual acuity
  • Color vision deficits
  • Weak or paralyzed muscles around the eyes
  • Eyes not moving together
  • Droopy upper eyelid
• Gastrointestinal
  • Unexplained liver failure
  • Impairment of the digestive tract muscles
  • Inability to swallow
  • Lack of appetite
  • Nausea
  • Stomach cramps
• Cardiovascular
  • Irregular heartbeat
  • Arrhythmia
  • Fluctuating blood pressure 
  • Unexplained heart block in a child
  • Lactic acid buildup
  • Cardiomyopathy
• Musculoskeletal
  • Pain or muscle cramping 
  • Non-coordination between the muscles
  • Inability to gain weight or grow at an expected rate
  • Poor muscle tone
• General
  • Lack of energy
  • Shortness of breath
  • Mouth sores
  • Fever
  • Dizziness
  • Congestion
  • Coughing
  • Dry skin
  • Kidney stones or swollen hands
  • Hearing loss
  • Hormonal imbalances
• Complications
  • Hearing loss
  • Diabetes
  • Lactic acidosis
  • Failure to thrive
  • Chronic fatigue
  • Heat or cold intolerance
  • Delayed milestone achievement 
  • Inability to fight typical childhood infections
  • Repeated infections and fevers with an unknown cause
  • Blindness
  • Deafness

Mitochondrial diseases are caused by genetic defects in the mitochondria. Healthy mitochondria use oxygen, sugar, protein, and fat from food to produce energy. Mitochondria that are defective owing to mutation may produce less energy, thus resulting in organ failure.

• Primary disease: Mitochondrial disease is a hereditary condition, which means that most people are born with it. It is inherited from one or both parents. In very rare cases, the condition is caused by a "spontaneous mutation," which arises at or before conception despite the presence of healthy (normal) genes in both parents.
• Secondary disease: It is also possible to develop mitochondrial illness later in life without having a basic DNA mutation. This is known as secondary mitochondrial disease. It may arise as a result of:
  • The natural aging process (mitochondria slow down and work less effectively as the body gets older)
  • Certain prescription medications
  • Damage to mitochondria from stressors such as smoking or alcohol abuse

Mitochondrial disease is rare but can affect people of all genders and ages.

Advances in medicine and research over the last decade have helped in understanding, diagnosing, and treating mitochondrial diseases. Unfortunately, no cure or treatment guarantees improved health or function. The objectives of supportive treatment for mitochondrial diseases may include:

• Alleviating symptoms
• Improving function 
• Slowing disease progression 

Common treatment options for mitochondrial dysfunction may include:

• Physical therapy
• Occupational therapy
• Respiratory therapy
• Speech therapy
• Massage therapy
• Stretching and relaxation exercises
• Exercise training
• Counseling
• Medications and supplements 

Medications

• Anti-convulsants
• Muscle relaxants
• Botox injections

Supplements

Several vitamin supplements have been found in a recent study to help reduce symptoms and enhance function. They are commonly referred to as the "mitochondrial cocktail." Your doctor may advise you to take some or all of the following supplements:

• Creatine monohydrate
• Vitamins C and E
• Alpha lipoic acid
• Co-enzyme Q10
• Riboflavin
• Thiamine
• L-carnitine
• L-arginine

This vitamin combination is intended to help compensate for shortages caused by improper mitochondrial energy production. Vitamins and supplements are currently the core treatment for mitochondrial diseases. They are believed to aid mitochondrial energy production and prevent toxic compound buildup within cells. 

Exercise 

Exercise is one of the most effective therapies for mitochondrial disease. Swimming, walking, cycling, weight lifting, and other activities may be recommended by a doctor, depending on your condition. 

Exercising promotes energy production in the body, which enhances mitochondrial function and increases the number of healthy mitochondria in cells. People who exercise learn to use oxygen more efficiently, resulting in a gradual increase in exercise tolerance. Your physician can help you design an exercise program tailored to your needs.

Dietary therapy

Understanding how foods affect your body and modifying your diet to what your body tolerates best is one way to manage your symptoms. Research has shown that a keto diet may be effective in some people; however, this may not be the cause for all people.

Other treatments

Optical aids

Hearing aids

Implanted cardiac pacemakers or defibrillators

Intravenous (IV) hydration and IV antibiotics

Treatment success varies from person to person, depending on the severity of the condition. Individuals with moderate symptoms may respond more positively to therapy than those with severe symptoms. However, treatment cannot reverse the harm that has already been done.

Because mitochondrial diseases are rare, limited systematic research on the average survival of people has been conducted. The average life expectancy is expected to increase as treatments and early detection methods improve. Scientific and technological advancements will allow for therapeutic breakthroughs in treating mitochondrial illnesses.

Receiving a diagnosis and living with mitochondrial disease can be difficult. 

Having a reliable network of family and friends that provide a support system can help improve your quality of life. Exercise and meditation can also help you relieve stress. Make use of community resources such as therapeutic programs to help make the condition more manageable.

As more people become aware of mitochondrial disease, additional treatment options may become available. It may help to stay informed on mitochondrial news and clinical studies that are taking place.