Klippel–Feil syndrome

Overview

Klippel–Feil syndrome (KFS) is a rare congenital condition characterized by the fusion of two or more cervical vertebrae (bones in the neck). This fusion results in limited neck mobility and a short neck appearance. The condition was first described in 1912 by Maurice Klippel and André Feil. Individuals with KFS often present with a triad of features: a short neck, low hairline at the back of the head, and restricted neck movement. However, the severity and presentation can vary widely. KFS may occur alone or in association with other skeletal, cardiac, renal, or neurological anomalies.

Causes

Klippel–Feil syndrome is caused by errors in the development of the cervical spine during early fetal life. In most cases, the exact cause is unknown, but some are linked to genetic mutations. Identified genes associated with KFS include GDF6, GDF3, and MEOX1. The condition can be inherited in an autosomal dominant or autosomal recessive pattern, though many cases are sporadic and not inherited. Disruptions in embryonic segmentation during the third to eighth weeks of gestation are thought to lead to vertebral fusion.

Symptoms

Symptoms of Klippel–Feil syndrome can range from mild to severe and may include:

• Short neck

• Low posterior hairline

• Limited range of motion in the neck

• Neck pain or discomfort

• Scoliosis (abnormal curvature of the spine)

• Hearing loss

• Neurological symptoms such as numbness, weakness, or balance issues (in some cases)

• Facial asymmetry or torticollis (twisted neck)

• Associated anomalies: congenital heart defects, renal abnormalities, cleft palate, or limb deformities

Not all individuals with KFS display the classic triad, and the condition may be identified incidentally during imaging for unrelated issues.

Diagnosis

Diagnosis of Klippel–Feil syndrome is typically made through clinical evaluation and imaging studies. Diagnostic procedures include:

• Physical examination: To identify characteristic features such as short neck, low hairline, and restricted motion

• X-rays: To visualize fused cervical vertebrae

• MRI or CT scans: For detailed imaging of spinal cord, vertebrae, and associated anomalies

• Hearing tests: To assess for conductive or sensorineural hearing loss

• Cardiac and renal evaluations: To detect associated structural abnormalities

• Genetic testing: In cases with family history or suspected syndromic involvement

Treatment

There is no cure for Klippel–Feil syndrome, and treatment is focused on managing symptoms and preventing complications. Management strategies include:

• Physical therapy: To improve neck strength, posture, and mobility

• Pain management: With medications or targeted therapies for chronic discomfort

• Surgical intervention: For spinal instability, severe deformities, or neurological compression

• Orthopedic bracing: In cases of scoliosis or other spinal abnormalities

• Audiologic care: Hearing aids or therapy for individuals with hearing loss

• Monitoring and management of associated anomalies: Such as heart, kidney, or airway conditions

Multidisciplinary care is often required, involving orthopedic surgeons, neurologists, ENT specialists, cardiologists, and physical therapists.

Prognosis

The prognosis for individuals with Klippel–Feil syndrome varies depending on the severity of vertebral fusion and associated abnormalities. Many individuals with mild forms live normal lives with minimal limitations. However, those with more complex forms may face lifelong orthopedic, neurological, or functional challenges. Early diagnosis, regular monitoring, and comprehensive supportive care can significantly improve quality of life and functional outcomes.