| Phenotype details |
no dysmorphisms; 5-6y-onset motor regression; 10y-lack of speech; 5y-stumbling and difficulty with ambulation, 10y-unable to walk unsupported; 7y-loss of skills started, 13y-severe contractures with inability to use hands; 8y-drooling, 10y-feeding problems and progressive dysphagia; 13y-G-tube dependent, 10y-lost continence; 6y-ataxic gait; 7y-nystagmus, 11y-dysconjugate gaze; 7y-increased deep tendon reflexes; dysarthria, spasticity, cerebellar signs (dysmetria, slow heel to shin, broad stance), 7y-positive Romberg and Babinksi; 20y-Vineland 3rd edition with significant delays across domains; epilepsy, 10y-myoclonus; EEG 13y-normal; MRI brain 7y-normal, 13y-diffuse cerebral atrophy, 20y-severe cerebral volume loss |