When my son was two or three and going for "Social Skills" at a community place, one child had Fragile X. He had a very long face and ears that stuck out--two characteristics I believe are part of Fragile X. He screamed a lot and, I have no idea if those with Fragile X are more severe, but he was a lot worse than most of the kids I know on the spectrum. None of this is "official" info, just my own observation of this child. He would not leave his mother to go in the room with other kids and would cling to her legs and cry, poor thing.
