What Causes Problems With The Mobility Of The Neck?

i am 30 and have always had problems with mobility in my neck after continuous complaints to my doctor about stomach problems and pain in both arms and my lower back i finally decided to look up why i may have these problems. I found klippel-feil syndrome and took it to my doctor and i told them i needed an x-ray. The x-ray showed that i have fusion from c-2 to c-6 now would this be klippel-feil or would there be other causes for this? Also when i was born i had a problem with my foot that was turned up and my head lay to one side.