I'd also like to add my story. I was born with a hip deformity. Treatment began when I was approximately 18 months old. I remember distinctly my abuse starting at this time. The reason I remember it so distinctly is the treatment consisted of sleeping with a bar with your shoes bolted to it (like a spreader bar). The abuse continued until age 14. It involved everything from inappropriate touching to anal rape. The emotional scars continue to this day in the form of PTSD and flashbacks.
I was introduced to BDSM by a wonderful, experienced Dom who realized what I was (submissive) and how to push me yet stay within my comfort zone. I experienced only 1 flashback which he immediatly recognized and treated lovingly.
I want to open a can of worms to ponder a question I have asked myself for a long time and probably will never have an answer to.
My first experience of sexual pleasure was while I was restrained. I have often wondered if somehow I became "wired" at that time to BDSM. A nature vs nurture sort of thing.
DISCLAIMER: I know there are MANY abuse survivors that are vanilla. That being abused does not necessarily predispose one to BDSM. My thoughts and questions are specifically my own. However, I would appreciate others thoughts and opinions.