| Characteristic | No. of patients* |
|---|---|
| Age, yr, mean | 52 |
| Age at diagnosis, yr, mean | 45 |
| Clinical features | |
| Muscle weakness or atrophy | 14 |
| Fatigue | 10 |
| Depression | 10 |
| Anxiety | 9 |
| White matter lesions on MRI | 9 |
| Hearing loss | 8 |
| Stroke or stroke-like episodes | 8 |
| Migraines or headaches | 6 |
| Cognitive impairment | 5 |
| Type 2 diabetes | 5 |
| Learning disability | 4 |
| Constipation | 4 |
| Dysphagia | 3 |
| Seizure disorder | 2 |
| Lipomas | 2 |
| Cataracts | 2 |
| Ptosis | 2 |
| Peripheral neuropathy | 2 |
| Short stature | 2 |
| Bipolar disorder | 1 |
| Personality disorder | 1 |
| Dysarthria | 1 |
| Cardiomyopathy | 1 |
| Arrhythmia | 1 |
| Recurrent miscarriages | 1 |
| Nystagmus | 1 |
| Ophthalmoplegia | 1 |
| Ataxia | 1 |
| Use of mitochondrial supplements | |
| Creatine | 13 |
| α-Lipoic acid | 13 |
| Riboflavin | 13 |
| Vitamin C | 13 |
| Vitamin E | 13 |
| Coenzyme Q10 | 13 |
Note: MRI = magnetic resonance imaging. *Unless stated otherwise.