Re: Math, chemistry, engineering?
You better hope it is a life style choice or behaviour disorder. If it's ever shown to be genetically based and a test is devised to detect it, you really will be thinking eugenics. Most people will consider it an abnormality and elect for an abortion as they do for dwarfism or down syndrome.
BTW, if you don't consider an inability to identify with your gender to be a disorder, then I'm not sure what would qualify as one.