Didn't you manage to read the third sentence?
"Scientists involved in that discovery have stated they expect that every step on the gender spectrum is largely caused by some or more of the same genes"
I suggest you read all the sentences, especially as that was a very short post, or you may easilly missunderstand what people are saying. Including following the link I'll be providing in a moment.
I wrote on this on my blog back in May. An important comment by Riki on Zoe Brain's blog is reproduced in that post http://caveofrationality.blogspot.co...causation.html Key piece worth quoting is:
So there's the referance that scientists involved in showing TS is biologically caused believe that CDing, as its part of that gender spectrum mentioned, will also be found to be similarly biologically caused. Not yet proved by science but predicted as likely by those scientists most expert in the subject.I interviewed Dick Swaab, whose lab produced the BSTc research that is the strongest evidence for a neurological correlate for trans...
..He also explicitly supported the idea that there is a biological causation for the whole range of gender identity variations:
"I think we talked about a scale like the Kinsey scale for sexual orientation – we should also have a gender identity scale. It is not either this or that; there is also something in between. The distribution will not be simple, but here will be people somewhere in the middle."
"So it is not the entire brain that is switching, it is some systems, and that may also be the explanation for the [gender identity] scale. Some systems do switch and others don’t and it depends on which systems have switched where you enter on the scale."