International GNAO1 Awareness Day is observed worldwide every October 1 to highlight a rare genetic neurodevelopmental disorder caused by mutations in the GNAO1 gene. This day aims to support affected families and encourage further research into GNAO1 disorders, which can lead to various neurological issues, including epileptic encephalopathy and movement disorders. The condition, first described in 2013, presents symptoms typically within the first year of life, with seizures often occurring in the first three months. Organizations such as the US-based Bow Foundation and other GNAO1 foundations from Italy, the Netherlands, Finland, and Spain promote this observance. The day emphasizes the need for better understanding and treatment options for GNAO1-NDD, which is currently incurable and requires symptom-focused management.