You didn't offend and I'm sorry if my comment seemed aggressive. We're all in the same boat here. There is actually a ton of research on it. I have a science background and am currently in medical school. I've looked into this stuff a lot. The fact that stutterers are much more likely than the general population to have relatives that stutters shows that there is a genetic component to it. Even with common genetic diseases, many cases are what's called "idiopathic". This means that the source can't be figured out. To my knowledge there are no papers out there that definitely link specific genes to stuttering, but just the fact that relatives are more likely to get it points to a genetic link. There were a few papers that I'd have to look for that did disprove any link between childhood trauma and stuttering however.