Is being gay or trans a sin? After all it is how we are born and if you believe God made everything, including humans then you have to believe that He made us as well. How is being born gay a sin any more than being born straight? Either way, sex still comes into the equation because of our innate human nature, but that is another matter for another day.
Needless to say, if it is a sin, well then - most good things in life are and have been called "sinful" - so what?