What are the signs and symptoms of Klippel Feil syndrome? Klippel Feil syndrome is characterized by the fusion of 2 or more spinal bones in the neck (cervical vertebrae). The condition is present from birth (congenital). The 3 most common features include a low posterior hairline (at the back of the head); a short neck; and limited neck range of motion. However, not all affected people have these features. This condition can cause chronic headaches as well as pain in both the neck and the back. KFS has been reported in people with a very wide variety of other conditions and abnormalities, including: scoliosis (curvature of the spine) cervical dystonia (painful, involuntary tensing of the neck muscles) genitourinary abnormalities (those of the reproductive organs and/or urinary system, including the kidneys) Sprengel deformity cardiac (heart) defects such as ventricular septal defect pulmonary abnormalities (relating to the lungs) and respiratory problems hearing deficits facial asymmetry, or other abnormalities of the head and face (such as cleft palate or hemifacial microsomia) torticollis central nervous system abnormalities (including Chiari malformation, spina bifida, or syringomyelia), and/or neurological symptoms other skeletal abnormalities (including those of the ribs, limbs and/or fingers) situs inversus short stature synkinesia (where movement in one hand involuntarily mimics the deliberate movement of the other hand) Wildervank syndrome Duane syndrome or other eye (ocular) abnormalities The Human Phenotype Ontology provides the following list of signs and symptoms for Klippel Feil syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormal vertebral segmentation and fusion 90% Cervical vertebral fusion (C2/C3) 90% Facial asymmetry 90% Limited neck range of motion 90% Low posterior hairline 90% Short neck 90% Vertebral segmentation defect 90% Webbed neck 90% Abnormality of the ribs 50% Abnormality of the shoulder 50% Congenital muscular torticollis 50% Hearing impairment 50% Scoliosis 50% Sprengel anomaly 50% Abnormality of limb bone morphology 7.5% Abnormality of the cranial nerves 7.5% Abnormality of the sacrum 7.5% Cleft palate 7.5% Cognitive impairment 7.5% Ectopic anus 7.5% Hemiplegia/hemiparesis 7.5% Posterior fossa cyst 7.5% Renal hypoplasia/aplasia 7.5% Spina bifida 7.5% Urogenital fistula 7.5% Ventricular septal defect 7.5% Scoliosis 30/50 Sprengel anomaly 21/50 Mixed hearing impairment 5/24 Bimanual synkinesia 9/50 Unilateral renal agenesis 7/45 Abnormality of cardiovascular system morphology 21/505 Abnormality of the pinna - Autosomal dominant inheritance - Autosomal recessive inheritance - Cervicomedullary schisis - Cleft upper lip - Conductive hearing impairment - Fused cervical vertebrae - Sensorineural hearing impairment - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.