The idea that sexual orientation is an inborn trait (whether true or not) was a powerful political strategy for gay rights, which has now been transferred to trans rights.
Is everyone who now identifies under the broad transgender umbrella 'born with it'. Seems unlikely.
In any case rights (e.g. privacy, autonomy) don't rely on a characteristic being in-born.
Every person is born with the type of body with the potential to produce sperm or the type which comes with egg on board, and it is impossible to switch between the two types (hence sex is immutable) .
This is unsurprising when you think about evolution
I was born this way (and so were you)