Klippel-Feil syndrome is a rare set of birth defects, or a syndrome, that is characterized by the abnormal joining (fusion) of two or more spinal bones in the neck (cervical vertebrae). Three major features result from the abnormality: a short neck, a limited range of motion in the neck, and low hairline at the back of the head. Most people have one or two of these features, but less than 50% of people affected have all three. Over time this condition may cause neck and back pain in affected areas, involuntary arm movements, joint pain (osteoarthritis) around affected areas, and nerve damage in the head, neck, or back, which can compress and damage the spinal cord. Other symptoms may include: hearing difficulties, malformed kidneys, and opening in the roof of the mouth (cleft palate), underdeveloped shoulder blades, and heart abnormalities.
Klippel-Feil syndrome occurs in approximately 1 in every 40,000 newborns, and females are affected slightly more often than males. This condition is inherited as either autosomal dominant or recessive depending upon where the gene change or mutation is located. We inherit our genes in pairs, one from each parent. Our genes are what control the growth, development and function of our bodies. Autosomal dominant means that if one parent has the condition (therefore the gene change or mutation) there is a 50% chance that they will pass it on to each of their children. Autosomal recessive means that each parent must be a carrier of the mutation (but not affected) and the child would need to inherit both copies of the gene change to be affected. When both parents are unaffected carriers, each of their children has a 1 in 4 chance of being affected. There are two dominant forms, type 1 and type 3 and type 2 is the recessive form. All three forms present with the same physical features. Treatment varies on a case-by-case basis depending on the specific features present.