Diagnosis
Evaluation may combine clinical history, examination, genetic testing, biochemical testing, imaging, and other targeted studies. Testing should be interpreted by qualified clinicians.
Mitochondrial disease
What is mitochondrial disease?
Mitochondrial diseases are a diverse group of disorders in which mitochondria cannot produce or manage cellular energy normally. They can affect almost any organ, especially the brain, nerves, muscles, heart, eyes, ears, liver, and endocrine system.
Symptoms and severity vary widely
Symptoms may begin at any age and can differ even among relatives with the same genetic change. Common features can include fatigue, exercise intolerance, muscle weakness, seizures, developmental differences, hearing or vision loss, neuropathy, diabetes, heart problems, gastrointestinal symptoms, or involvement of multiple organs.
These symptoms also occur in many other conditions. A symptom list cannot establish a mitochondrial diagnosis.
What causes it?
Primary mitochondrial disease is usually caused by a disease-associated change in mitochondrial DNA or in one of many nuclear genes needed for mitochondrial function. Inheritance can be maternal, autosomal dominant, autosomal recessive, X-linked, or new in the affected person.
“Mitochondrial dysfunction” in another illness is not automatically the same as a primary genetic mitochondrial disease.
Management
There is no single treatment for all mitochondrial diseases. Care is individualized, often multidisciplinary, and may include symptom management and condition-specific precautions.
Research
Natural-history studies, biomarkers, drug trials, genetic approaches, and patient registries are advancing, but availability and evidence differ by condition.
When to seek help
Contact a qualified clinician for new or changing symptoms. Use local emergency services for urgent or life-threatening concerns.
Condition library
Explore mitochondrial disease guides
MELAS
A mitochondrial syndrome that may involve stroke-like episodes, seizures, headaches, hearing loss, diabetes, muscle weakness, and other organ systems.
Read condition guidePOLG-related disorders
A spectrum of mitochondrial DNA maintenance disorders with presentations that can include epilepsy, neuropathy, ataxia, progressive external ophthalmoplegia, and liver disease.
Read condition guideTWNK-related disorders
Disorders of mitochondrial DNA maintenance that can include progressive external ophthalmoplegia, muscle weakness, ataxia, neuropathy, or severe childhood-onset disease.
Read condition guideOPA1-related disorders
A spectrum best known for dominant optic atrophy; some people also experience hearing loss, neuropathy, ataxia, muscle weakness, or external ophthalmoplegia.
Read condition guideLeigh syndrome
A genetically diverse progressive neurological disorder, usually beginning in infancy or childhood, associated with characteristic brain imaging findings and impaired energy metabolism.
Read condition guideLeber hereditary optic neuropathy (LHON)
A mitochondrial optic neuropathy that typically causes painless central vision loss, often in young or middle adulthood.
Read condition guideMERRF
Myoclonic epilepsy with ragged-red fibers is a multisystem mitochondrial syndrome that may include myoclonus, seizures, ataxia, and muscle disease.
Read condition guideSingle large-scale mtDNA deletion syndromes
A spectrum including Pearson syndrome, Kearns–Sayre syndrome, and progressive external ophthalmoplegia, with features that vary by age and affected tissues.
Read condition guideMT-ATP6-related disorders
A spectrum that includes NARP and maternally inherited Leigh syndrome, with variable neuropathy, ataxia, vision changes, developmental, and neurological features.
Read condition guideCommon questions
Diagnosis, symptoms, genetics, treatment, and daily life
Mitochondrial disease symptoms
Symptoms vary widely because energy-dependent organs can be affected in different combinations.
Read guideMitochondrial disease diagnosis
Diagnosis is a clinical and molecular process, not a single symptom checklist or screening test.
Read guideMitochondrial disease genetic testing
Testing may examine mitochondrial DNA, nuclear genes, or both, and the most informative sample can depend on the suspected condition.
Read guideMitochondrial disease treatment
There is no single treatment for all mitochondrial diseases; management is condition- and symptom-specific.
Read guideMitochondrial disease inheritance
Inheritance may be maternal, autosomal dominant, autosomal recessive, X-linked, or apparently new in the affected person.
Read guideMitochondrial disease life expectancy
There is no reliable single life-expectancy figure for mitochondrial disease because diagnoses and severity differ substantially.
Read guideMitochondrial disease in adults
Mitochondrial disease can begin in adulthood or persist from childhood, sometimes with subtle or multisystem features.
Read guideMitochondrial disease in children
Childhood presentations range from isolated findings to complex developmental and multisystem illness.
Read guideFinding a mitochondrial disease specialist
Specialist needs depend on symptoms and diagnosis; mitochondrial programs often coordinate genetics, neurology, metabolic medicine, and other disciplines.
Read guideSources
References and further reading
- MedlinePlus: Mitochondrial Diseases
- NINDS: Mitochondrial Disorders
- GeneReviews: Primary Mitochondrial Disorders Overview
- United Mitochondrial Disease Foundation
External sources are provided for context and do not imply endorsement of MDA.