Our applicant turns out to be a transgender—can we revoke the job offer?

Q. Our company has just made a job offer to a highly qualified man to work in our company’s IT department. During the final stages of our interviewing process, the candidate told us that “she” is transgendered —that she would be transitioning from male to female. We believe employing a transgender employee could be very disruptive and cause a morale problem in the company. Can we rescind the offer based on the candidate’s transgender status?