Down syndrome (DS) is one of the most common chromosomal disorders with mental retardation and some spesific physical and physiological defects. Recently, many advances have been made in pre-natal screening and detection; and the hope is that identification of more genes will lead to a better understanding of the molecular mechanisms underlying the pathologies, and hence to more effective therapy. This paper provides an overview on the discovery of Down syndrome through philately.

Keywords: Down syndrome, mental retardation, genetics, history, philately