CdLS Awareness Day, also known as Cornelia de Lange Syndrome Awareness Day, is observed on May 9. This day aims to educate the public about CdLS, a genetic disorder that affects approximately 1 in every 10,000 births in the US, and to provide support for those impacted by the syndrome. Typical customs include raising awareness through education, connecting with the CdLS Foundation, and encouraging donations to support affected families. The syndrome is characterized by slow growth, distinctive facial features, and potential intellectual disabilities. It is estimated that around 30,000 Americans live with CdLS, yet less than 10% are connected with the foundation, highlighting the importance of this awareness day. The event fosters understanding and community support for individuals and families navigating the challenges of CdLS.