Your child is very fortunate to have supportive parents that are there. The rest of the world is not related to your child and does not know your child. I surmise that your child was born with the genetic markers of a male child. 

Honest, kind people can and do have a genuine disagreement with the premise that gender can vary from genetic identity without significant mental impairment in most cases.

I hope that your child can find peace in this world. I also hope that your child can find the moral courage to accept that reasonable people can disagree with his choices and the grace to accept and tolerate those differences of opinion.