Syndrome characterized by the congenital fusion of any
two of the seven cervical vertebrae resulting in shortness of the neck,
restricted neck movements, and low posterior hair line. Other features
include congenital heart defect (e.g., ventricular septal defect) and
Facial asymmetry and short, webbed neck in a 17-year-old girl with Klippel-Feil syndrome.
Although this syndrome was first described in 1743 by the Swiss physician Albrecht von Haller
(1708-1777), it now bears the name of the two French neurologists, Maurice Klippel
(1858-1942) and André Feil (born 1884), who described the disorder in 1912.
Estimated at approximately 1:42,000 live births. Females
account for approximately 65%.
Autosomal dominant and autosomal recessive inheritance do occur, but
most cases are sporadic. Gene map locus is 8q22.2.
Vertebral malformation caused by failure of normal
segmentation of cervical somites during the third and eighth week of
gestation with resulting associated primary or secondary neurologic
defects. Four types are described:
- Type I: Extensive cervical and upper thoracic spinal fusion
- Type II: One to two interspace fusions often associated with occipitoatlantal fusion
- Type III: Coexisting fusion in the lower thoracic or lumbar spine
- Type IV: Klippel-Feil anomaly associated with sacral agnesis
Type I is 50 times less common than type II, but tends to present with the
classic triad (see Clinical Aspects) and is frequently associated with
birth injuries and other
major organ abnormalities. Practically, the presence of spine anomalies
in the form of hypermobility or spondylosis places these
patients at higher risk for spinal cord injury with minor trauma.
Clinical suspicion is confirmed by radiography. Lateral
flexion-extension radiographs of the cervical spine should be performed to
determine the motion range at each interspace. Once diagnosed, patients should be
followed with radiographic assessment at least annually.
The classic triad consists of short neck,
restriction of neck movement, and low posterior hair line. Of these,
restriction of movement is most common and occurs in up to 50% of cases.
The syndrome often remains unrecognized because the neck may appear normal
and the patient is asymptomatic until later in life. Presentation may be
with neurologic deficit that occurs either spontaneously or after minor
trauma. Syncopal attacks may be precipitated by sudden rotary movements of
the neck. Other skeletal anomalies include cervical vertebral fusion,
hemivertebrae, sacral agenesis, scoliosis (either primary or secondary) in up to 60% of cases,
spinal canal stenosis, and
torticollis. Other findings include webbed neck, Sprengel deformity
(both, small and elevated scapula) in 30%, genitourinary abnormalities in
35 to 65% (hydronephrosis, renal ectopia, renal agenesis, horseshoe kidney, anomalies of the
congenital heart disease in 15% (particularly ventricular
septal defect), deafness in 30% (conductive and/or sensorineural), synkinesia (mirror movements) ...