http://www.pinknews.co.uk/2009/12/11/gene-discovery-could-make-gender-reassignment-easier/

QuoteThe discovery of a single gene which controls gender could pave the way for simpler treatment of trans people.

Back in '07, researchers published in New Scientist (journal from Australia / New Zealand way) research on the same thing. 

Hopefully, this will also make it easier to pass a trans-inclusive ENDA here in the US.