| Phenotype details | kyphoscoliosis with gibbus, ogival palate; 5-10y-onset motor regressio, 15y-severe motor problems; 11m-first words, 5y-speech skills at level of 2.5y, expressive language problems, dysarthria; 28y-wheelchair-bound; 35y-dysphagia with aspiration and esophageal reflux; completely dependent, wheelchair bound; ataxia, choreoathetosis, generalized dystonia; divergent strabismus, mild proptosis; hyperreflexia; axial hypotonia; intellectual disability (first years); 13.5m-febrile seizures, photosensitive epilepsy, myoclonic epilepsy; EEG 10y-abnormal, 13y-diffuse slowing, bilateral generalized bursts of spikes and waves and polyspikes; MRI brain 34y-atrophy (cerebral, cerebellar, brainstem, corpus callosum); muscle biopsy normal |