Medicine in stamps: history of Down syndrome through philately.

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.