WHAT IS MITO
What is mitochondrial disorder?
Mitochondrial disease, or mitochondrial disorder, refers to a group of disorders that affect the mitochondria, which are tiny compartments that are present in almost every cell of the body. The mitochondria’s main function is to produce energy. More mitochondria are needed to make more energy, particularly in high-energy demand organs such as the heart, muscles, and brain. When the number or function of mitochondria in the cell are disrupted, less energy is produced and organ dysfunction results.
Depending on which cells within the body have disrupted mitochondria, different symptoms may occur. Mitochondrial disease can cause a vast array of health concerns, including fatigue, weakness, metabolic strokes, seizures, cardiomyopathy, arrhythmias, developmental or cognitive disabilities, diabetes mellitus, impairment of hearing, vision, growth, liver, gastrointestinal, or kidney function, and more. These symptoms can present at any age from infancy up until late adulthood.
Mitochondrial disease diagnosis
Every 30 minutes, a child is born who will develop a mitochondrial disorder by age 10. Overall, approximately 1 in every 4,300 individuals in the United States has a mitochondrial disease. Given the various potential presentations that may occur, mitochondrial disease can be difficult to diagnosis and is often misdiagnosed.
There are various methods to examine if an individual has mitochondrial disease. These include genetic diagnostic testing, genetic or biochemical tests in affected tissues, such as muscle or liver, and other blood or urine based biochemical markers. However, our knowledge is still growing and we do not yet know all of the genes that could potentially cause mitochondrial disease.
Mitochondrial disease causes
Mitochondria are unique in that they have their own DNA called mitochondrial DNA, or mtDNA. Mutations in this mtDNA or mutations in nuclear DNA (DNA found in the nucleus of a cell) can cause mitochondrial disorder. Environmental toxins can also trigger mitochondrial disease.
Mitochondrial disease symptoms
Mitochondrial disorder symptoms include:
Loss of muscle coordination, muscle weakness
Neurological problems, including seizures
Autism spectrum disorder, represented by a variety of ASD characteristics
Visual and/or hearing problems
Developmental delays, learning disabilities
Heart, liver or kidney disease
Gastrointestinal disorders, such as severe constipation
Increased risk of infection
Thyroid and/or adrenal dysfunction
Dysfunction of the autonomic nervous system
Neuropsychological changes or dementia characterized by confusion, disorientation and memory loss
Treatment for mitochondrial disease
Currently there is no highly effective treatment or cure for mitochondrial disorder. The management of mitochondrial disease is supportive therapy, which may include nutritional management, exercise and/or vitamin or amino acid supplements.
Knowing the underlying cause of your or your child’s condition will help your medical team determine the best course of treatment. Dr. Amel Karaa at Massachusetts General Hospital works closely with your primary care physician, neurologist, and other specialists to manage your day-to-day medical needs.
Long-term care may involve a variety of specialists, including neurologists, endocrinologists, ophthalmologists, audiologists, cardiologists and nephrologists.
For patients with mitochondrial disease with no known genetic cause, yearly follow-up appointments are typically recommended as mutations in new genes causing mitochondrial disease are discovered all the time.