Klippel-Feil syndrome

Klippel-Feil syndrome, abbreviated KFS and also called cervical vertebral fusion syndrome, is a rare congenital condition in which any two of the seven bones of the neck, the cervical vertebrae, are abnormally fused. The fusion can limit how far the neck moves and can make the neck look short, sometimes with a low hairline at the back of the head, although most affected people show only one or two of these features and the condition may go unnoticed without medical imaging. It is hard to diagnose because it is a label for a group of patients with many different abnormalities who share fused or segmental cervical vertebrae; it is not always genetic and is not always known at birth. The disease was first reported in 1884 by the French physicians Maurice Klippel and Andre Feil, and in 1919 Feil proposed a wider classification that also took in deformation of the lumbar and thoracic spine.