Mitochondrial Disease in Adults

  • As varied as in children, more complicated to diagnosis because adults have acquired other diseases through the years. Mitochondrial diseases tend not to present as catastrophic events.
  • Childhood onset mitochondrial diseases that become increasingly obvious as the person ages
  • Muscle: new muscle weakness, cramping, fatigue
  • Brain: migraine, stroke or stroke-like events, dementia, MS-like presentation
  • Endocrine: diabetes (~5% of DM may be due to the mtDNA 3243 mutation)
  • Cardiac: early cardiomyopathy, cardiac conduction defects (association of LHON with WPW, etc)
  • Systemic: CFS-like illness (Chronic Fatigue Syndrome – like illness)

Many experts refer to Mitochondrial Disease as the “Notorious Masquerader” because it wears the mask of many different illnesses.

Additional Adult Brief Differential Diagnoses to Consider

  • Primary endocrine disease
  • Vitamin deficiency: B12
  • Homocystinuria and associated disorders
  • Primary muscle disease: polymyositis, dystrophin associated glycoprotein muscular dystrophies
  • Chronic fatigue syndrome
  • Autoimmune disorders
  • Glycogen storage disorders
  • Depression and related psychosomatic disorders
  • Other neurodegenerative disorders (MS, ALS, HD, combined systems degeneration)

Mitochondrial disease is diagnosed by:

  • Evaluating the patient’s family history
  • Performing a complete physical examination
  • Performing a neurological examination
  • Performing a metabolic examination that includes blood, urine, and optional cerebral spinal fluid tests
  • Performing other tests, depending on the patient’s specific condition and needs. These tests might include:
    • Magnetic resonance imaging (MRI) or scan (MRS) if neurological symptoms are present
    • Retinal exam or electroretinogram if vision symptoms are present
    • Electrocardiogram (EKG) or echocardiogram if heart disease symptoms are present
    • Audiogram or BAEP if hearing symptoms are present
    • Blood test to detect thyroid dysfunction if thyroid problems are present
    • Blood test to perform genetic DNA testing

More invasive tests, such as a skin or muscle biopsy, might be performed as needed and recommended by your doctor.