You bring up these examples that I can only answer if I am actually in one. My short answer is I don't know how parents react when this happens, I don't know how I would react if one of my Boys, I would imagine I would be heartbroken and would love them and would try to explain regardless of how a person "feels" they are what they are. Boys are Boys and Girls are Girls and God created boys and girls for a purpose....But that is a canned answer as I don't know how I would handle exactly.  You have no expertise in Biology or Psychiatry...spare me the rhetoric.