21 March the International Day of people with Down syndrome (World Down Syndrome Day). This date is entered in the calendar in 2006. The initiative belonged to the participants VI symposium on the topic. In Russia Day Down Syndrome was first noted in 2011.
Date March 21 was not chosen by accident — it is a symbolic designation of the Down's syndrome, caused by trisomy of one of the chromosomes in a human suffering from this disease , chromosome 21 is present in three copies. Translated into "the language of the calendar " happened 21th of the third month.
English physician John Langdon Down (John Langdon Down, November 18, 1828 — October 7, 1896 ) in 1862 first described the syndrome, which later received his name as a form of mental illness. Communication between the origin of congenital syndrome and chromosome numbers revealed in 1959 by the French geneticist Jerome Lejeune (J