Interlove happens. Sometimes you get something other than XX or XY. Sometimes your testicles don't produce enough hormones and you get the ability to grow breasts. Maybe your ovaries are actually testicles and you can choose whether you are male are female. Maybe you have ovaries, testicles, and a snake?
So what? stuff happens. stuff in genetics happen. Down syndrome, for example, is a genetic slip up.
If your body just made you have a mind of a girl, and a body of a boy, you are transgender. It's not normal, but that doesn't mean it doesn't happen.
Biological love: Male, Female, Both, Neither
Gender Identity: Male, Female, Both, Neither, Fluid
They have no correlation with each other. Most of the time they are the same, but that doesn't mean the "non-normal" happens.