| Neurological characteristics |
Central nervous system |
Stroke-like episodes, migraine, epilepsy, ataxia, dementia, Parkinsonism, developmental delay, psychiatric or mood disorder, developmental regression |
| Visual system |
Ptosis, progressive external ophthalmoplegia, optic atrophy, retinitis pigmentosa |
| Acoustic system |
Sensorineural hearing loss |
| Skeletal muscle |
Myopathy, exercise intolerance |
| Peripheral nervous system |
Peripheral neuropathy |
| Non-neurological characteristics |
Digestive system |
Gastrointestinal dysmotility; malabsorption, intestinal pseudo-obstruction, chronic villous atrophy |
| Kidney |
Fanconi syndrome, renal tubular acidosis, focal segmental glomerulosclerosis, renal failure, adrenal insufficiency |
| Metabolic/endocrine apparatus |
Lactic acidosis, multiple lipomatosis, short stature, diabetes, hypothyroidism, hypoparathyroidism |
| Heart |
Cardiomyopathy, conduction defect |
| Hematopoietic system |
Sideroblastic anemia |
