| Phenotype details |
see paper; ..., facial dysmorphism; axial hypotonia; 8m-sit; 15m-walk; speech delay; still walking; 17y-regression onset; dystonia; ataxia; pyramidal syndrome, cerebellar dysarthria, slow dysmetric eye saccades; 7m-spasm, myoclonus seizures, 17y-myoclony seizures; EEG spikes and waves; no atrophy; no periventricular anomalies; muscle biopsy normal |