There are only two genders. Gender expression =/= gender. Gender expression is a social manifestation of a biological thing called GENDER influenced by SEX.
Well I have put yes only two however its not exactly what I think
Biologically its Male Female and Hermaphrodite this last option is incredibly rare (0.2% to 1.7 % )
But thats it there is no other biological thing than that
But the psychological sex of someone well I have a hard time understanding there are anything other than male or female whether that is natural or trans variant
While I find it offensive that the government would inquire about my gender on some form I had to fill out recently (I put down 'Attach Helicopter', I really don't care what other people want to call themselves. However that gets defined, be it 'gender' or 'gender expression' or what have you. There is some debate recently over these definitions, but I think I'm going to take a wait-and-see approach.