I'm not suggesting there's any association between klienfelter syndrome and transgenderism or transsexuality; only that they all work to prove that the classic idea of two genders or two states of gender is totally bull-pucky.

Neither sex (the body's apparent gender) or gender (one's own self-identification and social role) are discrete binary categories.

Well it was a large development effort, but we have modernized our gender categories to use Trans Woman and Trans Man instead of MTF or FTM and also added Non Binary.

  There is a lot of talk of Gender Identity as different from Sex. Usually it follows on the line that gender is what you feel you are, and sex is what you physically are, or what your biology tells us you are.