| Phenotype details |
15y-deceased; no dysmorphisms; 5-6y-onset motor regression; speech meeting milestones initially, 7y-dysarthria, 12y-loss of speech; met early gross motor skills milestones, 4m-rolled over, 5m-sit,, 10m-walk, always toe walked; 5y-developing spasticity, 5y-loss of gross motor skills, 9y-wheelchair-bound; 5y-loss of fine motor skills; 10y-dysphagia; 10y-G-tube fed; dystonia present, no ataxia; 11y-dysconjugate gaze; sustained clonus; axial hypotonia, progressive with loss of head control; Babinski present bilaterally; no intellectual disability, cognition appeared intact throughout; epilepsy, no clear clinical seizures but ‘staring spells’ that resolved with Lamictal; EEG 9y/13y-mild background slowing; EEG 9y/1y-normal; MRI brain 8y-‘Bulky’ corpus callosum, mild cerebellar volume loss, large left middle cranial fossa arachnoid cyst, 10y-marked cord thinning on spine |