World Down Syndrome Day was created to celebrate the lives of people with Down syndrome and to make sure they have the same freedoms and opportunities as everybody else.
21st March (21/3) matches the 3 copies of chromosome 21. This is unique to people with Down syndrome.
World Down Syndrome Day has been an official part of the United Nations calendar since 2012. You can read the full history of World Down Syndrome Day at the bottom of this page.
On 21st March each year, Down Syndrome International calls everyone to action with a theme to ensure the human rights of people with Down syndrome and works with members to organise worldwide activities and discussions.
What is Down Syndrome?
Down syndrome is a naturally occurring genetic condition caused by the presence of an extra copy of chromosome 21. While most people are born with 23 pairs of chromosomes for a total of 46, individuals with Down syndrome have 47. Because chromosomes act as the body’s “instruction manual,” this additional genetic material alters the typical course of physical and mental development.
This condition affects approximately 1 in every 800 babies and occurs naturally with no known cause. It is not a disease to be cured, but rather a fundamental part of a person’s identity. Although it often leads to varying levels of intellectual disability and certain common health conditions, these challenges do not prevent individuals from leading successful lives. With the right support and resources, people with Down syndrome attend school, hold jobs, and contribute vibrantly to their communities.