How are mitochondrial diseases diagnosed?
Because mitochondrial diseases affect so many different organs and tissues of the body, and patients have so many different symptoms, mitochondrial diseases can be difficult to diagnose. There is no single laboratory or diagnostic test that can confirm the diagnosis of a mitochondrial disease. This is why referral to a medical facility with physicians who specialize in these diseases is critical to making the diagnosis.
Diagnosis starts with a series of examinations and tests that may include:
- A review of a patient’s family history
- A complete physical examination
- A neurological examination
- A metabolic examination that includes blood and urine tests, and, if needed, a cerebral spinal fluid test (spinal tap)
Other tests, depending on the patient’s symptoms and the areas of the body that are affected, might include:
- Magnetic resonance imaging (MRI) or spectroscopy (MRS) for neurological symptoms
- Retinal exam or electroretinogram (ERG) for vision symptoms
- Electrocardiogram (EKG) or echocardiogram for symptoms of heart disease
- Audiogram or auditory-brainstem evoked responses (ABER) for hearing symptoms
- Blood test to detect thyroid dysfunction if the patient has thyroid problems
- Blood test to perform genetic DNA testing
More advanced testing could include biochemical testing, which looks for changes in body chemicals that are involved in energy making. Biopsies (samples) of skin and muscle tissue may also be performed.