If anyone else suggests that maybe the reason he is so small is that he has Celiac Disease, I might lose it. Unless Hongmei is feeding him nothing but noodles while I'm away, I really doubt that. We don't feed him wheat.
I kind of hope that we are, in some way, accidentally starving the kid, because that is easy to fix. Poor nutrition can lead to low IGF-I. Changing his diet is something we can do. It's hard to believe he's not getting enough food just at the moment when he tucked into his salmon last night, and did a good job on his scrambled eggs this morning, but diet is easier to fix that a malfunctioning pituitary gland.