GNAO1 and early-infantile DEE: The term GNAO1 encephalopathy-related disorders, or GNAO1 encephalopathy, refers to a group of de novo GNAO1 mutations linked to neuro-developmental disorders, primarily developmental and epileptic encephalopathy 17 (also known as early infantile epileptic encephalopathy) (DEE) and neurodevelopmental disorder with involuntary movements (NEDIM) (Briere et al., 2023; Nakamura et al., 2013).