Ds just scared me to death, he had a fragile X blood test and of course got upset, but it was over and he was calming down, had the plaster on his hand was about to choose a sticker, the next thing his wole body tensed up (like when they do them shocks on the heart) and his eyes rolled in his head, i could just see the whites of his eyes...he was totally stiff.
It lasted about 5 seconds but was awful 
i ended up in tears, then he vomited everywhere...anyone seen this before?
The doc checked him over, and said it is quite common, but i have never heard of that before. They just said keep an eye on him over the next 24hrs.