<unk>  (KFS), also known as cervical vertebral fusion<unk> , is a rare congenital condition characterized by the abnormal fusion of any two of the seven bones in the neck (cervical vertebrae). It results in a limited ability to move the neck and shortness of the neck, resulting in the appearance of a low hairline. The<unk>  is difficult to diagnose, as it occurs in a group of patients affected with many different abnormalities who can only be unified by the presence of fused or segmental cervical vertebrae. KFS is not always genetic and not always known about on the date of birth. The disease was initially reported in 1884 by Maurice<unk>  and André<unk>  from France. In 1919, in his Doctor of Philosophy thesis, André<unk>  suggested another classification of the<unk> , encompassing not only deformation of the cervical spine, but also deformation of the lumbar and thoracic spine.
Klippel–Feil syndrome
Srb's anomaly
Treacher Collins syndrome
Iniencephaly
Klippel–Trénaunay syndrome
Pelger–Huët anomaly
Laurence–Moon syndrome
Langer–Giedion syndrome