Down syndrome and genetics - a case of linked histories

Down syndrome, the most common genetic cause of intellectual disabilities, was first described in 1866, during an era of great change in our understanding of genetics and evolution. Because of its importance, the history of research on Down syndrome parallels the history of human genetics. In many instances, research on Down syndrome has inspired progress in human genetics. In this article, we describe the interplay between advances in the understanding of genetics and the understanding of Down syndrome from its initial description to the present, and on the basis of this historical perspective, speculate briefly about the future of research on Down syndrome.