March 21 (3/21) is World Down Syndrome Day. It was chosen to signify the uniqueness of Down Syndrome in the triplication (trisomy) of the the 21st chromosome and is used synonimously with Down Syndrome.
Commemoration of World Down Syndrome Day began in March, 2006. It has grown manifold globally. The observance is used to promote awareness and understanding of Down syndrome and related issues; and to mobilize support and recognition for the dignity, rights and well-being of persons with Down syndrome.