World Down Syndrome Day
' ('WDSD) is marked each year on March 21. 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.
- "Getting ready for World Down Syndrome Day 2020 - 21/03/2020 00:00:00". Down Syndrome International.