I’ve been trying to get some guidance here for several years. Requests for assistance are acknowledged, but not answered.
To explain, people born with Intersex conditions have bodies that are neither 100% male nor 100% female. Transsexuality is a kind of Intersex where the neurology, the brain, is mismatched with the rest of the body, or most of the rest of the body, as Transsexuals often have other Intersex conditions too.,
The plain fact is that most if not all organisations that view transsexuality as a moral evil on religious grounds are not aware of any distinction between transsexuality and homosexuality - except to believe that transsexuality is ultra-homosexuality, the most perverse of the perverted and the ultimate in moral degradation.
Unfortunately few have any regard for medical science, or science in general. When one believes the bible is literally true, inerrant, and the sun orbits an earth 6000 years old, any appeal to science is likely to be seen as yet more evidence of evil-utionist conspiracy.
Oddly, the Christian mainstream is one of the few religions that should be more understanding, not less, of Intersexed people (and I include Transsexuality there, as the medical evidence indicates that’s what it is). The first line of Matthew 19:12 mentions the Intersexed - those eunuchs born of their mothers womb - and Isaiah 56:3-5 states categorically that they’re exempt from the normal rules of male and female behaviour. They must do what is pleasing to God and keep the Sabbath - that’s it.
There are those who say that men are born men, women are born women, and Intersex and Transsexuality are illusory. There is no Gender, only Sex, and Sex is defined by what you look most like at birth. They fall silent when confronted by medical conditions such as 5alpha-reductase-2 deficiency (5alpha-RD-2) and 17beta-hydroxysteroid dehydrogenase-3 deficiency (17beta-HSD-3) where apparently female infants masculinise so they become apparently male by their mid-20’s. About 2/3 accept or even welcome the change as a cure for their existing transsexuality, while to the remaining third, it’s a descent into nightmare - they become transsexual women with male bodies.
Perhaps such people, like the blind man in John 9:1-12, are there to show that transsexuality is a medical and biological, not a moral issue. That God does not make mistakes when He decides that some should have bodies of uncertain gender, or have brains of one gender and bodies of another. And that neither condition is the result of moral corruption.
However, all that aside, what exactly is Church teaching on the subject? This is especially important in view of His Holiness’s recent statements demanding respect for Church teaching that there is only male and female, and that the idea of “gender” rather than strict corporeal sex at birth is a danger to Humanity and contradicts God’s natural order.