Klippel-Feil Syndrome is characterised by improper segmentation of cervical segments resulting in congenitally fused cervical vertebrae. The disease is isolated Klippel-Feil syndrome (EFO_0700054). Also known as: Klippel-Feil malformation, Klippel-Feil sequence, congenital cervical vertebral fusion, congenital fused cervical segments, nonsyndromic Klippel-Feil syndrome.