Researchers, to my knowledge have not identified genes directly related to transsexuality.  There is no work I know of using the HGP attempting to find them either.  I'm by no means on the cutting edge of this though.  If you want to look for research specific to genetics and transsexuality, you could look through the journals stored online at JSTOR.

If your point is that all human traits are rooted in the expression of DNA, I'm in complete agreement.  The authors in my study are alluding to how the presence of aromatase affects DNA expression on a large scale in brain development.  What they call "the female brain" is a tendency of comparative structural differences between the developed brains of normal men and women.  For example men will generally have larger hemispheres (I think, don't quote me on that) while women have porportionately thicker corpus callosums facilitating better left to right and right to left integration.  There are also other observed structural differences between the sexes.  It's a bit of a leap to stay that these structural differences lead to behavioral and intelligence differences, but if you come from the "form dictates function" school, one would likely look at it as possible.

It would also be a bit of a stretch for me to say that this is what defines true M to F transsexuality as I would have to look at this in a bubble, free from other influences.

-- Modified on 4/4/2008 7:57:28 AM