"loD be' je ngaghbogh loD" (Man who has sex with men and women, i.e. bisexual) and "be' mojpu'bogh loD" (Man who has become a woman) are both immensely burdensome, and not really accurate. A canonical way of expressing LGBT people would go a long way in bring Klingon to other interested people.
Comment below with feedback and suggestions.
While I suppose something to refer to gay/queer people other than Har'eyngan, I've found Dop to be a good verb for [to be] transgender.