Episodic Choreo-Dystonic Storm in an Infantile-Onset Movement Disorder: Think of G Protein Subunit Alpha O1 Gene Defect!

While ATPase Copper Transporting Beta ( ATP7B ), Dystonia-1 ( DYT-1 ), Lysine (K) Methyl transferase 2B ( KMT2B ), and Adenylate Cyclase 5 ( ADCY5 ) gene mutations are well-characterized causes of childhood-onset choreo-dystonic movement disorders, G protein subunit alpha O1 (GNAO1)-related disorders are not commonly suspected. The GNAO1 gene is crucial for neuronal transmission, and its mutation has been linked to neurodevelopmental delay, infantile-onset epilepsy, and movement disorders. To the best of our knowledge, only five Indian cases have been reported to date. We report a 9-year-old girl with predominant choreo-dystonic manifestations along with dyskinetic storm, i.e., episodes of significant worsening in involuntary movements following febrile episodes. Her brain magnetic resonance imaging (MRI) was unremarkable. She presented to us in a dyskinetic crisis, which responded to oral haloperidol. Thus, GNAO1 -related disorder must be suspected in a child with developmental delay, infantile- to childhood-onset seizures with/without movement disorders, along with episodes of dyskinetic crisis related to stress or febrile episodes.