Thanks to Mara and Yesh for the genetic angle.
Here's a moral and perhaps an ethical question... Increasingly gene-therapies may be able to alter undesireable traits in children. Obviously, life-threatening traits will probably be targeted first, but traits that can affect quality of life might also be targeted.
If you were a parent and your child were likely to be genetically prone to transgendry, gender ambivalence, dysmorphia, androgyny etc... would you remove the trait? Would you ever deliberately introduce one of those traits to the child's genotype?
Why or why not? And what (if anything) would you tell the child?
That technology doesn't exist, and it would have to exist for me to make an informed decision. It would really depend on what the genetic tampering actually did.
Considering that some intersex people end up miserable because their parents chose to have the wrong procedures for them after birth, I'm a bit leery of genetic tampering that would basically be the same thing.
And being transgender isn't an undesirable trait with proper technology. It's mostly painful because of current circumstances. (Transphobia, lack of understanding, and limited transitioning technology for transsexual people.)
With future technology, I think it would be much more responsible to simply allow people to transition when they want, and to focus on eliminating the stigma.
I certainly would be okay if I didn't have to worry about discrimination or upsetting my family, didn't have to justify myself, and hadn't grown up in an environment where most of my life, my only knowledge of transgender people came from Jerry Springer, Ace Ventura, and similar "classy" stuff. And with better physical change options, there'd be even less of a problem. (First priority should be better options for trans men. I've heard there are military experiments with growing organs for injured soldiers, including penises, so this could be reality.)
In theoretical future world, I'd have transitioned by the age of 18-20 or so, if not earlier, and would be accepted for who I am, and would never have to worry about whether I was visibly trans or not. (Really, many transsexual people already feel fine once they transition, even with the problems we have now. With future technology, it'd probably not be a very big deal at all.)
Anyway, in actual future, genetic tampering wouldn't work very well, most likely. It'd probably just be a weapon for authoritarian parents who want even more absolute control over their children's minds and bodies. And I'm against that.
Oh, and I was mostly talking about transsexual people in most of this post. Out of all of the categories of transgender, we're probably the ones with the most justification to "cure," and I'm still very opposed to that.
Anyone who wants to eliminate genes for being androgynous, bi-gender, genderqueer, or a-gender should not be allowed to have or raise children. That's bigotry and abuse, pure and simple, without any sort of justification at all.
(Transsexual people have a physical problem. Other transgender people don't have a problem at all. But I'm sure the bigots would assume we all have a mental problem, and want to alter our genes accordingly.)