From http://kfsalliance.org/the-facts/
Klippel-Feil Syndrome (KFS) is a rare skeletal condition in which there is abnormal union or fusion (congenital synostosis) of two or more bones of the spinal column (vertebrae) within the neck (cervical vertebrae).
The spinal column or backbone is made up of 33 irregularly-shaped bones known as vertebrae. These bones are divided into different categories. The first seven vertebrae, beginning at the base of the skull, are known as the cervical vertebrae. KFS primarily affects the cervical vertebrae. Some affected individuals may have an abnormally short neck, restricted movement of the head and neck, and a low hairline at the back of the head (posterior hairline). The disorder is present at birth (congenital), but cases may go undiagnosed until later during life when symptoms worsen or first become apparent. In some individuals, KFS can be associated with a variety of additional symptoms and physical abnormalities. These may include abnormal curvature of the spine (scoliosis) and/or vertebral instability, spina bifida occulta, raised scapula (Sprengel’s deformity), absent rib(s) and other rib defects including cervical ribs, other skeletal abnormalities including skeletal malformations of the ear, nose, mouth and larynx including hearing impairment and cleft palate, malformations of the head and facial (craniofacial) area; anomalies of the urinary tract and/or kidney including absent or horse-shoe kidney; or structural abnormalities of the heart (congenital heart defects), mirror movements, webbing of the digits and digital hypoplasia. Neurological complications may result due to associated spinal cord injury. In some cases there may be progressive osteoarthritis.
Reproduced in part with permission from the National Organization for Rare Diseases.
Me again: Sometimes KFS is genetic, sometimes, it's a fluke, so we went to U of U to try and find out. What we learned is that 1 in 40,0000 people can exhibit KFS. Of those, most of the time the children have cervical fusion the C 2-3 vertebrae. JB's fusion is in C 5-6, and also in T2-3. She does exhibit the highlighted symptoms, but very mildly, and in fact, if you didn't know what to look for you wouldn't notice she has any malformation at all. So, with her type of KFS, it is even more rare, occurring 1 in 100,000 people. Because of this rarity, the fact that Bill and I are not first cousins, and there is no recorded malformation in either of our family histories, the doctors felt this occurrence of KFS is most likely a fluke. However, there is still a possibility for a genetic predominance of the condition and further investigation is required. They were really excited to see that one of my eyes doesn't focus correctly which is an indicator of Duane's Syndrome, which often occurs in people with KFS. So I have been asked to have my eyes checked again to determine if this is the case. So, it could be another data point to JBS situation being genetic. It's just that RIGHT NOW there aren't enough individuals with this type of KFS to contribute to a larger body of knowledge through a specifically targeted case study.
They told us to come back in 4-5 years, when hopefully they will have more knowledge of genetic markers that could lead to this syndrome. Basically, right now, they just don't know.
