The onset of abnormal hyperkinetic movements ranged from 4 months to 9 years of age (median 2 years). Within the cohort, there was considerable clinical heterogeneity with regard to motor semiology and severity. Profound hypotonia preceded the onset of abnormal movements in patients 1, 2, and 7, who later developed dystonia, followed by severe episodes of paroxysmal choreoathetosis. Gradual development of facial dyskinesia was also reported in these patients (videos 1, 2, and 5). Patient 3 experienced continuous generalized choreoathetosis and facial dyskinesia. At the age of 4, because of repeated and prolonged infective episodes, status dystonicus developed, requiring intensive care, with sedation, ventilation, tracheostomy, gastrostomy, and metabolic support. MRI showed progressive cerebral atrophy. Status dystonicus persisted, with rise in creatine kinase (CK) and renal failure, leading to multisystemic deterioration and death. Patient 4 exhibited complex motor stereotypies and a dyskinetic motor pattern (video 3). Patient 5 manifested almost continuous orolingual dyskinesia. She also had mild dyskinetic movements of the upper limbs (video 4). Patient 6 exhibited complex rocking, staring, back arching, and pelvic thrusting movements, associated with hand-to-mouth complex stereotypies.
