World Down Syndrome Day
Description
The 21st day of March (the 3rd month of the year) was selected to signify the uniqueness of the triplication (trisomy) of the 21st chromosome which causes Down syndrome.
The 21st day of March (the 3rd month of the year) was selected to signify the uniqueness of the triplication (trisomy) of the 21st chromosome which causes Down syndrome.