The Barrie Police Service is proud to recognize World Down Syndrome Day (WDSD) on March 21. World Down Syndrome Day is a global awareness day which has been officially observed by the United Nations since 2012. Read about how WDSD came about on the United Nations resolution page. The date for WDSD being the 21st day of the 3rd month was selected to signify the uniqueness of the triplication (trisomy) of the 21st chromosome which causes Down syndrome.