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|Classification and external resources|
|This article may be too technical for most readers to understand. (December 2010)|
|Classification and external resources|
Klippel–Feil syndrome is a rare disease, initially reported in 1912 by Maurice Klippel and André Feil from France, characterized by the congenital fusion of any 2 of the 7 cervical vertebrae.:578 The syndrome occurs in a heterogeneous group of patients unified only by the presence of a congenital defect in the formation or segmentation of the cervical spine. Klippel–Feil syndrome can be identified by shortness of the neck. Those with the syndrome have a very low hairline and the ability of the neck to move is limited.
Numerous associated abnormalities of other organ systems may be present. This heterogeneity requires comprehensive evaluation of all patients and treatment regimes that can vary from modification of activities to extensive spinal surgeries. Furthermore, it is unclear whether Klippel–Feil syndrome is a unique disease, or if it is one part of a spectrum of congenital spinal deformities. Klippel–Feil syndrome is usually diagnosed after birth.
The most common signs of the disorder are a short neck, low hairline at the back of the head, and restricted mobility of the upper spine.
Associated abnormalities may include:
The disorder also may be associated with abnormalities of the head and face, skeleton, sex organs, muscles, brain and spinal cord, arms, legs, fingers and heart defects. These heart defects often lead to a shortened life expectancy, the average being 35–45 years of age among males and 40–50 among women. This condition is similar to the heart failure seen in gigantism.
In 2011, a study identifying the occurrence of symptoms of 100 patients was published.
Although the actual occurrence for the KFS syndrome is unknown, it is estimated to occur 1 in 40,000 to 42,000 newborns worldwide. In addition, females seem to be affected slightly more often than males.
In 1912, Maurice Klippel and Andre Feil independently provided the first descriptions of Klippel–Feil syndrome. They described patients who had a short, webbed neck; decreased range of motion (ROM) in the cervical spine; and a low hairline. Feil subsequently classified the syndrome into 3 categories:
However, recently, Dino Samartzis and colleagues in 2006 proposed 3 classification-types that specifically addressed the cervical spine anomalies and their associated cervical spine-related symptoms, with additional elaboration on various time-dependent factors regarding this syndrome.
Treatment for Klippel–Feil syndrome is symptomatic and may include surgery to relieve cervical or craniocervical instability and constriction of the spinal cord, and to correct scoliosis.
Failing non-surgical therapies, spinal surgery may provide relief. Adjacent segment disease and scoliosis are two examples of common symptoms associated with Klippel–Feil syndrome, and they may be treated surgically. The three categories treated for types of spinal cord deficiencies are massive fusion of the cervical spine (Type I), the fusion of 1 or 2 vertebrae (Type II), and the presence of thoracic and lumbar spine anomalies in association with type I or type II Klippel–Feil syndrome (Type III).
Adjacent segment disease can be addressed by performing cervical disc arthroplasty using a device such as the Bryan cervical disc prosthesis. The option of the surgery is to maintain range of motion and attenuate the rate of adjacent segment disease advancement without fusion. Another type of arthroplasty that is becoming an alternate choice to spinal fusion is Total Disc Replacement. Total disc replacement objective is to reduce pain or eradicate it. Spinal fusion is commonly used to correct spinal deformities such as scoliosis. Arthrodesis is the last resort in pain relieving procedures, usually when arthroplasties fail.
The heterogeneity of the Klippel–Feil syndrome has made it difficult to outline the diagnosis as well as the prognosis classes for this disease. Because of this, it has complicated the exact explanation of the genetic etiology of the syndrome.
The prognosis for most individuals with KFS is good if the disorder is treated early on and appropriately. Activities that can injure the neck should be avoided, as it may contribute to further damage. Other diseases associated with the syndrome can be fatal if not treated, or if found too late to be treatable.
Pedigree analysis has identified a specific location of a gene on a chromosome for Klippel-Feil Syndrome. Mutations in the GDF6 and GDF3 genes have also been identified to cause the disease. Although some people with Klippel–Feil syndrome do not have identified mutations in the GDF6 or GDF3 genes. In this case, the cause of the condition in these individuals is unknown. GDF6 and GDF3 genes provide the body with instructions for making proteins involved in regulating the growth and maturation of bone and cartilage. These proteins actively regulate cell growth in embryonic and adult tissue. GDF6 specifically is involved in the formation of vertebral bones, among others, and establishing boundaries between bones in skeletal development while GDF3 is involved with bone and cartilage growth. Mutations cause reductions in these functional proteins but, it is unclear exactly how a shortage in these proteins leads to incomplete separation of the vertebrae in people with Klippel–Feil syndrome. However, when the GDF6 gene was knocked out in mice, the result was the fusion of bones. Only by identifying the link between the genetic etiology and the phenotypic pathoanatomy of Klippel–Feil syndrome will we be able to rationalize the heterogeneity of the syndrome.
These mutations can be inherited in two ways:
In 2009, archaeologists excavating at a Neolithic site in northern Vietnam discovered the remains of a young man around age 25 living between 2000 BC and 1500 BC with Klippel–Feil syndrome, who had apparently been supported by his subsistence-level community for at least a decade before his death.
This article incorporates information in the public domain prepared by the National Institute of Neurological Disorders and Stroke.