World Down Syndrome Day is creatively on March 21. Why is that creative? The numeric date, 3/21, is a nod to the chromosome alteration that causes Down Syndrome: an extra (or third) 21st chromosome, is the cause of the most common chromosomal condition, which affects 1 in 700 people in the US—each year, 6000 babies with Down Syndrome are born. [1] A feature of Down Syndrome is the distinct facial features of people with DS. Despite the common features of a “flattened” facial profile and nose, small head, mouth, and ears, and short nick, people