Kelkelkel, hi.
I think you have more than one issue here. The lies, the deception, the prostitution is one thing, and has nothing to do with the gender issues, I feel.
Obviously, I dont know your ex, and can only go by what you say. I would be surprised if he was truly transgender, as it might have been quite hard for him to deceive you so long, live like a man in a heterosexual relationship, if he truly felt he was a woman trapped in a mans body.
I would think he is bisexual, with transexual tendencies. You say he look like a clown. Most transgender people I have met go to great lengths trying to look like a normal woman. Not a caricature of a woman. (Like I feel transsexuals do)
We have a little boy in my sons school. He, or she, has some real gender issues. He complained early that he should be a girl. It has nothing to do with sex, it is about not being comfortable in the body, and the gender framework associated with that body. He wanted a girls childhood. Long hair, hair clips, pretty skirts, play with dolls, and talk about ponies. He is lucky in that our local GP is transgender herself (born a male) and picked up on the childs frustration. (Gp went through a gender operation several years ago so that he could become a woman and live life as female. It is not about escorts, sex, and dressing up with fake eyelashes. It is about dressing up in the morning, going to work, do your job, your shopping, cook dinner and have your life, but in the body that matches your persona and your emotions) This child is now 11, and have started hormone treatment to delay puberty. This will give the child a chance to be more mature before making the final decision. In case this was just " a phase". But he goes to school as Andrea, play with the girls only, dressed like a girl, has long plaited hair, and you could not see that this is a boy at all.
In either case. I doubt your dd will inherit some transgender gene. Children are young, and accept most things as normal, unless we tell them something is bad or shamefull, they wont think it.
There was a documentary on BBC last year about transgender children, you might be able to find it to watch on Iplayer.