"Syndrome" is actually a Greek word that means to run together. It is a word used by doctors when a particular collection of features are seen together. Many people think that the word syndrome means mental retardation but this is not true. There are over a thousand syndromes in the medical literature, many of them very rare, and new syndromes are being described every year. There are so many syndromes that many doctors and specialists many not have heard of Cornelia de Lange Syndrome.