Where’s the element of choice? I’m naturally heterosexual through no merit of my own, that’s how I am. The closest we can find to sexual identity disorder in the CC is homosexuality:2357 Homosexuality refers to relations between men or between women who experience an exclusive or predominant sexual attraction toward persons of the same sex. It has taken a great variety of forms through the centuries and in different cultures. Its psychological genesis remains largely unexplained.
2358 The number of men and women who have deep-seated homosexual tendencies is not negligible. This inclination, which is objectively disordered, constitutes for most of them a trial. They must be accepted with respect, compassion, and sensitivity. Every sign of unjust discrimination in their regard should be avoided. These persons are called to fulfill God’s will in their lives and, if they are Christians, to unite to the sacrifice of the Lord’s Cross the difficulties they may encounter from their condition.
Being attracted to same-sex people is not a choice. My being attracted to women is not a choice. Acting on my heterosexual attraction is a choice, the only choice for homosexuals is whether they act on their attraction or not. As for transgenderism, I believe it affects a small minority in the population, but I believe it’s genuine. With all the things that can go wrong physically (Google images can be absolutely shocking), how does the Pope know it’s impossible for someone to have all the internal makeup of a girl yet have a male body? I believe transgenderism will likely be mentioned alongside homosexuality in the next Catechism. BTW I’m not condoning either homosexuality or body mutilation (in the case of transgender people), neither is the Catholic Church, obviously. But the element of choice is simply nonexistent.