Mitochondrial Disorders

Overview

Mitochondrial disorders happen due to inherited or spontaneous genetic mutations or deletions. When these mutations or deletions happen in either the mitochondria or the portion of the cell containing the majority of the cell’s genetic information, the nucleus, they can cause errors in your cells’ energy-producing machinery.

Any organ system can be involved in mitochondrial disorders, however they tend to affect organs requiring a great deal of energy. The most commonly affected systems include:

• Brain
• Heart
• Kidneys and endocrine system
• Liver
• Nervous system
• Respiratory system
• Skeletal muscles

Many mitochondrial disorders appear in childhood. Others reveal themselves later in life. The severity of symptoms depends on your age at onset of the disorder and the number of organ systems involved. Life expectancy cannot be predicted and may vary considerably, even among affected family members.

Diagnosis

Diagnosing mitochondrial disorders is difficult, and the process usually requires more than one method.

Diagnostic testing may include:

• Magnetic resonance imaging (MRI) of your brain
• Heart tests (electrocardiogram and echocardiogram)
• Vision and hearing exams
• Neurologic evaluations
• Blood tests (metabolic testing and/or specific mitochondrial disease testing)
• Muscle biopsy (to see how well your mitochondria are making energy)

Genetic Counseling

The diagnostic process will also include genetic testing. After genetic testing is completed, you may meet with a genetic counselor to discuss the test results. IU Health genetic counselors are affiliated with Riley Hospital for Children at IU Health and the IU School of Medicine Division of Clinical and Biochemical Genetics. A counselor will explain your specific condition, the recurrence risk for other family members and generalized treatments.

Treatment

Treatments will not reverse the disease process, but they can improve some of the symptoms you or your child may be experiencing. Your treatment plan may include:

Avoiding Physiologic Stress

Abnormalities of temperature regulation are fairly common in individuals with mitochondrial disorders. You should avoid exposure to cold, as severe heat loss may result. Cover all exposed body parts when you go out into the cold. You also may not be able to sweat normally. To avoid heat exhaustion and heat stroke on hot days, dress lightly and consider staying indoors in an air-conditioned environment.

Disease Management

If you have a mitochondrial disorder, your disease management will be more supportive. Part of disease management may also include diagnosis and treatment of other related diseases such as:

Developmental Delays

Developmental delays are very common with mitochondrial disorders due to the frequent muscle and neurologic involvement. Developmental issues can range from mild — with mastery of skills only a bit later than normal — to severe, in which basic motor or intellectual skills are never obtained.

Gastrointestinal (GI) Issues

Mitochondrial disorders can cause slow motility in the GI tract resulting in constipation and rarely, vomiting.

Cardiac Dysfunction

Cardiomyopathy, or poor heart function, is often a symptom with mitochondrial disorders. When multiple systems are involved, cardiac dysfunction may be a complication.

Epilepsy

Seizures may be a symptom of your mitochondrial disorder. Anti-convulsion medicines can reduce the frequency of seizures.

Muscular Dystrophy

Some forms of muscular dystrophy are caused by mitochondrial disorders.

Nutrition Education

A registered dietitian experienced in metabolic disorders can recommend proper caloric intake and amounts of fat and iron you need to function and remain healthy. Because your body cannot make the energy it requires, you should avoid fasting.

Occupational Therapy

Occupational therapy assists you in learning or maintaining certain skills of daily living. These skills can include getting dressed, bathing and eating.

Physical Therapy

Physical therapy helps you build strength in your bones and muscles to learn and maintain motor skills.

Speech Therapy

Speech therapy can help you learn techniques to improve and maintain your verbal communication skills.

Supplements and Vitamins

Supplements and vitamins such as coenzyme Q10, carnitine and riboflavin allow for proper energy formation. Your doctor may recommend these supplements to improve your body’s ability to make energy and slow the progression of your disease.