| Typical Onset | Typically presents in early childhood (1-4 years), though juvenile and adult-onset variants exist |
| A467T | The most prevalent mutation, accounting for approximately 23% of all disease-causing alleles<sup>[1]</sup> |
| W748S | Common in European populations |
| E873X | A nonsense mutation found in certain populations |
| P905L | Associated with milder phenotypes |
| Neurological | Severe seizures (often intractable), developmental regression, ataxia, peripheral neuropathy, cortical blindness |
| Systemic | Lactic acidosis, hepatopathy (progressive liver failure), myopathy, failure to thrive |
| Databases | OMIMOrphanetClinicalTrialsPubMed |