This rocked my world, because longitudinal studies on gender reassignment occur about as often as blue mice:
Today's issue of the AMA Journal _Pediatrics_ contains a study that has the potential to radically alter the concept of immutable gender. (It also raises some disturbing ethical questions the choice of the child involved) It involves the second case of sex reassignment of a child who suffered an accident during a circumcision, who was then reassigned as a female. This differs from the first case in that it was successful. Rather than try to explain it here, let me refer you to an online summary at:
The online _Pediatrics_ has not yet upgraded their website to show the new table of contents or any abstract of the study--I will post an URL when we find one.