The trans sign seems to be a very regional thing.
Responses I've recieved
The linguaphiles say:
Trans is the sign for recently, but flipped around. That is is, sign recently, then turn your finger to face the other way.
FTM is F-T-M across the chest.
I don't know MTF because I don't have any deaf MTF friends. - larkie
larkie described it the way I sign it. I'm from Utah, and it's what I've seen used around here for it. - sliverchick
I'm seconding this just by remembering the correction given by my last ASL instructor. - vhsdit03
I was taught "trans" was the 'T' sign being used in the sign for "change". - admettre
In the PNW we use a variant of the sign for sex (x by the ear... not the sign for intercourse). We make the double x handshape with the index and middle finger and touch the index finger to the face (right under the ear like in sex) and then rotate to touch the middle finger in the same spot. Represents going from one sex to the other.
I know of no different signs to distinguish trannsexual and transgender. - ironmysandwich
Sign for sex = letter 'x'(palm facing out) - touch next to ear then touch side of chin.
I use this to mean trans = letter 'x' (palm facing out) - touch next to ear, turn hand so 'x' now has the palm facing you and touch side of chin.
There are also a few other signs that I use/know, depending on my meaning. - karisitas
The "x" sign that people above are describing is mostly used for "transsexual" (in my experience). I use a different sign for "transgender" or "trans" in general. I made a video awhile ago for someone else that has both the signs "transsexual" and "transgender" (located here). - kailen (That link is the video posted above.)
(to kailen) I use the sign you presented for trans/transgender as the general sign for trans. - zenlari
Hm. In Philadelphia area, people use the OPEN-FIVE hand against the center of the chest facing out and turn it clockwise against the chest into the FLAT-O. - pretendsuperman
I'm deaf and use ASL, so I can answer this question :)
Yes, there's a sign for transgender. The hand [behaves] similarly to the way "beautiful" is signed. It starts in the middle of the chest, palm in, open hand, then you twist the hand while closing the hand at the same time so the final shape is a bent-O handshape with the fingers pointing towards the chest. It's basically "beautiful inside", really. - rmpalpha
I should probably add that the sign is probably only a few years old (I first saw it three years ago or so), but it has pretty widespread use in the Bay Area in California, which is where I live now. I think the sign has also spread across the country, but I can't be sure of that, though. - rmpalpha
(re: the sign larkie described) Well, the sign you described is another sign that I've seen, but I've heard that it's a bit politically incorrect since the sign implies a reversal of the person's sex. But again, this could be a regional thing - the "beautiful inside" sign that I described is common in the Bay Area where I live.
No idea about the MTF/FTM concept. I would guess that people just spell it as it's an acronym - rmpalpha
needstrayjacket agrees with rmpalpha.