What is mitochondrial disease?
Mitochondrial diseases are a group of disorders related to mitochondria, which are tiny parts of cells that produce energy. Often called the “powerhouse of the cell,” most cells in your body have mitochondria. When the mitochondria are not functioning properly, energy levels are depleted, causing cells to be damaged or stop working. Mitochondrial disease can exist in one or more areas of the body, especially those that use high amounts of energy to stay healthy and active, like the heart, brain, or muscles.
Penn Medicine specialists are experts in diagnosing and treating complex illnesses like mitochondrial disorders. Our ongoing research focuses on finding the underlying causes of mitochondrial disease and creating better ways to treat it.
Types of mitochondrial disease
There are many types of mitochondrial syndromes, and their symptoms and treatments vary widely. A sampling of mitochondrial disease types includes:
- Kearnes-Sayre syndrome (KSS): Symptoms usually appear before the age of 20 and often affect the eyes.
- Leigh syndrome: This syndrome affects a baby’s nervous system and usually starts in the first year of life.
- Myoclonic epilepsy and ragged-red fiber (MERRF) syndrome: This type affects the nervous system, muscles, and other areas of the body.
- Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome: This syndrome affects many areas of the body, including the brain, the nervous system, and muscles.
- Leber hereditary optic neuropathy (LHON): This type can cause a rapid loss of vision, leading to legal blindness.
Mitochondrial disease symptoms
Symptoms of mitochondrial disease depend on which parts of the body are impacted. They may be mild or severe and appear at any age from birth into adulthood. Some of the more common symptoms include:
- Muscle pain or weakness
- Hearing or vision loss
- Gastrointestinal issues, including vomiting
- Constipation and diarrhea
- Seizures
- Migraines
- Poor growth or cognitive development in children
- Breathing issues
Causes of mitochondrial disorders
You may be born with a mutated gene that leads to mitochondrial illness. Mutations can come from one or both of your biological parents, while some mitochondrial DNA mutations are inherited through the birth mother only. Research is ongoing to pinpoint the exact cause and nature of these genetic conditions. When caused by a genetic mutation, the condition is considered a primary mitochondrial disorder.
People without a genetic mutation can also develop the disease. Primary diseases that can lead to the development of secondary mitochondrial disorders include type 1 diabetes, cancer, multiple sclerosis, Alzheimer’s disease, and muscular dystrophy.
Diagnosing mitochondrial disease
Mitochondrial diseases can be difficult to diagnose because they often impact multiple areas of the body at the same time and mimic other conditions. Your physician will begin by discussing your medical history, performing a physical exam, and running blood and urine tests. Neurological tests and imaging may also be performed, along with tests related to genetic causes or specific symptoms, such as vision or hearing tests.
Mitochondrial disease treatment
While there is no cure for mitochondrial disease, treatments can help you maintain your health and avoid serious complications. Treatment often centers around medications, supplements, exercise, and diet. Physical or occupational therapy and assistive devices may also be recommended. Speak with your physician about the most appropriate treatments for your type of mitochondrial disease.
Finding solutions for complex disorders
At Penn Medicine, we treat a wide variety of different mitochondrial disorders. Our specialized care is based on ongoing research into conditions caused by changes at the cellular level, including those with genetic causes. We have the experience needed to detect mitochondrial diseases and create innovative treatment plans to help you manage symptoms and stay healthy.