well there is a by percentage higher number of IS people within the Trans community as it CAN lead to dysphoric feelings regarding ones physical gender. Intersex is a more broad category than we allow for. as there are 52 genes that together make up a persons sex, and no one person is entirely male or female, its what makes us different. If we fight to suggest that being TS ISNT a mental illness, and claim its medical, surely if its medical it must be in some way physical, and thus an is related condition? anyway enough blabbering
and none of the above: dont tell me no, the body doesnt magically grow a third arm because it really wants to.... there are things we dont know, but magically swapping gender isnt one of them...