Here's something interesting; what the author came up with actually closeyl resembles a real syndrome- Turner's. You can read about it here:
http://en.wikipedia.org/wiki/Turner_syndromeThe thing is, for Mashiro's prognosis to be Turner's, he would have never gotten his period, because people with Turner Syndrome are sterile. I think it may still be possible, but I haven't seen it.
Anyway, yeah: although many of the physical symptoms don't match Mashiro, the physiological ones are pretty in-stride. Interesting stuff!
Ps... I own all ten books. XD