In 1912, Klippel and Feil  first reported on a patient with a short neck, a low posterior hairline, and severe restriction of neck movements due to complete fusion of the cervical spine, the classic clinical triad which is the hallmark of Klippel-Feil syndrome (KFS). It is estimated to occur in 1 in 40,000 to 42,000 newborns worldwide. Mutations in the GDF6 and GDF3 genes can cause KFS . But in some people there are no identified mutations in the GDF6 or GDF3 genes, and the etiology remains unknown. Mutations in MEOX 1 have been found to occur in association with Klippel-Feil syndrome .
Most cases of Klippel-Feil are sporadic. Some cases are due to autosomal dominant or autosomal recessive inheritance. It is a rare skeletal disorder primarily characterized by abnormal union or fusion of two or more cervical vertebrae. Other commonly associated anomalies include scoliosis, renal abnormalities, Sprengel deformity, deafness, synkinesia and congenital heart disease. The most common heart disease variant was ventricular septal defect. Less commonly associated were ptosis, lateral rectus palsy, facial nerve palsy and upper extremity anomalies.
There are 3 variants of KFS. Type I is an extensive abnormality where elements of several cervical and upper thoracic vertebrae are incorporated into a single block. In type II variant, failure of complete segmentation occurs at one or two cervical interspaces. Type III variant includes type I or II deformities with coexisting segmentation errors in the lower thoracic or lumbar spine. Type II is considered to be the most common form. C2-3 and C5-6 are the interspaces commonly involved [4-12]. The main anaesthetic concern with these patients is a potential unstable cervical spine and abnormal atlanto-occipital junction prone to an increased risk of neurological damage. Hence, their anaesthetic management should be carefully planned with patient involvement keeping in mind the other abnormalities associated with the condition.