PROJECT SUMMARY Glucose transporter 1 deficiency (G1D) constitutes an increasingly recognized cause of epilepsy, intellectual disability and motor control dysfunction. This summit proposal will catalyze the conjunction of several important but still disjointed developments in need of cross-fertilization. Rapid scientific, patient organization and information dissemination advances have made, for the first time, research on G1D approachable from a meaningful, patient-centered perspective. This means that harmonizing the collective voices of the scientific and patient community represented by the Glut1 Deficiency Foundation can greatly propel further progress. Although prevalence estimates are likely to change, about 1% of idiopathic generalized epilepsy or 1 in 23,000 births have been associated with G1D. Nevertheless, there is still no effective treatment. Yet, our recently adopted Team Science perspective and work in numerous single laboratories elsewhere have been yielding steady benefits. For example, we have contributed from the molecular characterization of mutation pathogenicity to the isolation of a key neural circuit involved in epileptogenesis, including the first rigorous trial of a dietary treatment, all under NIH sponsorship. Still, numerous additional approaches worldwide have also proven as fruitful or promising. Therefore, we propose to join the patient community with many of the leading investigators in the field in a summit. An example of the effectiveness of such collaborative work are our 2020 international diagnostic and treatment consensus recommendations, which already stand in need of revision given how rapidly the field is advancing. We also aim to reach consensus, or at least lay the groundwork, on the best animal models to share, the most informative biomarkers, the main disease phenotypes and their evolution across the lifespan, and the most effective clinical trial and data sharing approaches, given the need to unify concepts and disseminate resources. None of this can be accomplished by any single laboratory or team working in isolation. Instead, our approach will be open, transparent and international. The summit will benefit from 1) extensive previous expertise with scientific and patient centered G1D conferences and additional multi-lingual online events organized according to rigorous metrics, 2) existing partnerships with sister G1D patient organizations across the world, 3) the accessibility of the proposed location, which has been home to the largest clinic focused on G1D, 4) the strong support of some of the leading researchers not only in G1D but also in related fields such as dementia, cancer and epilepsy where metabolism is important, and 5) robust diversity and event safety plans. We expect ample dissemination of the proceedings via several mechanisms, thereby propelling a transformation of the G1D field for years to come, including the development of a network of investigators informed by patient needs and the creation of a framework for future revisions.

PUBLIC HEALTH RELEVANCE Glucose transporter 1 deficiency syndrome (G1D) is most often associated with lifelong medication-refractory neurological dysfunction. At present, G1D can only be alleviated by interventions such as the ketogenic diet, which can be poorly tolerated and afford only an incomplete restoration of neural function. A better understanding of G1D via the organized interaction of public advocates, scientists and clinicians in a summit fulfills the NIH mission by expanding current perspectives on new fundamental aspects of brain function and on the development of new therapies guided by a strong patient focus.