Neurodevelopmental and Movement Disorder Due to a Mutation in the GNAO1 Gene: A Case Report

Introduction: We present the case of a patient with a de novo heterozygous probably pathogenic variant c.545C>T (p.Thr182Ile) in the GNAO1 gene that is probably pathogenic in relation to a neurodevelopmental disorder and movement disorder. Case Report: A female patient who started at 3 months with severe neurodevelopmental delay, and subsequently myoclonus, orofacial dyskinesia, and choreoathetosis, without seizures. Metabolic and structural causes were investigated and, finally, whole exome sequencing in trio identified a de novo heterozygous, probably pathogenic, variant c.545C>T (p.Thr182Ile) in the GNAO1 gene. Conclusions: Early recognition of neurodevelopmental delay and abnormal movements are determinants of an etiological approach to a neurological disorder. The use of whole exome sequencing should be promoted if a structural and metabolic diagnosis has been ruled out as the identification of a specific condition affects its management and prognosis, and guides genetic counseling.