World Down Syndrome Day (WDSD), is on 21st March. On this day, Down syndrome organizations (INCLUDING INDIAN ORG)throughout the world organize and participate in events to raise public awareness of Down syndrome.
Down syndrome was first determined a chromosomal disorder in 1959 by French pediatrician and geneticist, Jérôme Lejeune.

source=Wikipedia,&http://www.worlddownsyndromeday.org/india