This congenital syndrome usually results in moderate to severe mental and physical disabilities. Earlier, many children died of serious medical problems in infancy because their needs were not anticipated. This is no longer the case, and it is expected that most will live into adulthood.
In 1933, Dr. Cornelia de Lange, a Dutch paediatrician, described two children with similar features. She is now generally credited with describing the collection of symptoms comprising the syndrome that bears her name. The syndrome is sometimes referred to as Brachmann-de Lange Syndrome, after Dr. W. Brachmann who described a similar patient in 1916.
The exact incidence is unclear, but it is thought to be between 1:10,000 and 1:30,000 live births.