Google Dr Vincent Harley and his work on transsexuals and you will find that in fact being trans has actually recently been found to have a strong correlation to a previously unknown form of androgen insensitivity.
What was not known until about three years ago was that there was a form of AIS which affected ONLY the functioning of the androgen receptors in brain tissue. Males with this gene fault are always strongly transgendered as the androgen receptors in the brain do not work properly.
So it's actually a lot more similar than you think. Sadly though it will take about two decades, and two or three duplicate studies confirming the results, before the work that Dr Harley had done penetrates the thick skulls of those who, like the compilers of DSM V, eroneously believe that there is no physical cause to our condition.
