Honestly, I think it's more a result of parents. A boy finds himself enjoying more feminine things and the parent encourages it as a sign that he is a girl. The trans-gender thing honestly seems to me to be only increasing in commonality because of the emphasis placed on it right now. People see something in themselves that has very little substance, then they build it up until it becomes the reality. It's kind of the "cool" thing these days to be part of the "LGBT" crowd, to be perfectly honest, and I think there are many members of that crowd who are only a part because they want to be. It doesn't help when there's actually a very vocal part of that crowd that decries anyone who isn't a part of it as inferior and detestable, with some cherry-picked examples of that inferiority/detestability that an unfortunate amount of people, mostly younger people, take as divine truth.

But then again, I have very little experience with transgender and have only personally known one transgendered individual, so I am not the best person to make judgements on them and the reasons for such an increase, particularly in children. I only speak on what I observe.