| Phenotype details |
13y-decline in scholar performance (impairments in memory and attention); 14y-tonic-clonic seizure (further seizures characterized by staring spells and palpebral myoclonus); mild daily fluctuating ataxia, distal tremor, bradylalia, borderline intellectual functioning (IQ 73 Wechsler scale); EEG diffuse sharp-and-wave complexes; MRI and MR Spectroscopy (MRS) shrunken cerebellum with reduction of the N-acetyl aspartate peak, without progression over time; antiepileptic drugs (including valproic acid, levetiracetam and lamotrigine) ineffective in complete control seizures; stable clinical course; double-membrane bound granular and osmiophilic inclusions cytoplasm dermal fibroblasts and myelinated fibers on skin biopsy |