Rare genetic neurodevelopmental disorders, such as Syt-1 or Baker Gordon Syndrome (BAGOS) arise from mutations in genes essential for brain development and function, often disrupting neurotransmission and neuronal connectivity. These conditions present with a wide range of symptoms including developmental delays, seizures, motor and behavioral challenges, and vary widely in severity. These disorders are complex, and they remain poorly understood and lack effective treatments. Natural history and clinical genetic studies are crucial for mapping how these disorders progress, improving diagnostic accuracy, and guiding therapy development. A major focus is identifying reliable biomarkers (genetic, imaging, and physiological) to track disease severity and support clinical trials. This study will securely collect and analyze data to better understand disease impact, develop patient-derived model systems, and build resources to support future treatments.