Abstract: GNAO1-associated disorder is a rare disease and an example of developmental and epileptic encephalopathies. Caused by ca. 150 different dominant missense mutations in the gene encoding the major neuronal G protein Gαo, it spans a wide range of neurological clinical manifestations, that may include epileptic seizures, motor dysfunctions, developmental and intellectual delay, and other symptoms (Sáez González et al., 2023). As of today, tools to predict the disease severity and prognosis, as well as responsiveness to current and developing therapies, are missing. Our recent study (Solis et al., 2024) has peeled, layer by layer, cellular and molecular deficiencies of a large panel of pathogenic GNAO1 variants, seeking quantitative correlations with the clinical disease manifestations. This analysis resulted in the identification of two pathogenic characteristics that may serve as molecular biomarkers of the disease. The first is the drop in plasma membrane localization of certain pathogenic variants, which correlates with the existence of seizures in the anamnesis. The second is the strength of neomorphic interactions with the molecular chaperone Ric8B, which correlates with the overall disease severity. Identification of the predictive disease biomarkers sheds light on the molecular etiology of GNAO1 encephalopathy and is expected to improve patient care, follow-up, and treatment.