Mitochondrial Disease
Mitochondrial disease refers to a group of rare genetic conditions that affect the mitochondria, the parts of cells that produce energy.
Overview
Mitochondrial disease refers to a group of rare genetic conditions that affect the mitochondria, the parts of cells that produce energy. Because energy is needed throughout the body, mitochondrial disease can affect many organs and systems, including the brain, muscles, eyes, heart, liver and nervous system. Symptoms and severity vary widely between individuals and between specific mitochondrial conditions.
Causes and Genetics
Mitochondrial disease can be caused by changes (mutations) in either mitochondrial DNA or nuclear DNA. Some mitochondrial DNA changes are inherited through the maternal line, while nuclear gene changes may follow autosomal recessive, autosomal dominant or X-linked inheritance patterns. In some people, the genetic cause is not identified immediately and diagnosis may require specialist testing.
Symptoms and Features
Symptoms vary depending on which organs and tissues are affected.
Characteristic Symptoms and Features
- Muscle weakness, exercise intolerance or fatigue
- Neurological symptoms such as seizures, developmental delay, movement problems or stroke-like episodes
- Vision or hearing problems
- Feeding difficulties, gastrointestinal symptoms or poor growth
- Heart, liver, endocrine or kidney involvement in some individuals
Other Associated Symptoms and Features
- Symptoms may begin in infancy, childhood or adulthood
- Symptoms may fluctuate, worsen during illness or progress over time
- Different family members may be affected in different ways
Mitochondrial disease is an umbrella term, and individual diagnoses may have distinct features and management needs.
Treatment
Supportive care may include physiotherapy, occupational therapy, nutritional support, seizure management, hearing or vision support, cardiac monitoring and coordinated specialist follow-up. Care is often provided through mitochondrial, metabolic, neurology, genetics or other specialist services.
Research and Future Directions
Research is focused on earlier diagnosis, improved genetic testing, better understanding of disease mechanisms, supportive care, reproductive options and emerging targeted or gene-based therapies. Patient experience research also helps identify where delays occur and how diagnostic pathways can be improved.