S.V.
I think Suzi is right...I've worked for social services in Georgia (where, basically--your cousin is also your brother). Lots of clear autism there...signs were usually seen early (I frankly think it's over diagnosed). You can't judge one 2 year old from another. 50 words is no longer the "requirement", as all children are different. I know a child who cuddled, kissed, giggled, made eye contact and had everything done FOR him...he didn't talk until he was 3...he's 6 and perfectly fine, doing well in school and some sort of advanced "belt" in karate. His mom, my best friend, went and had a speech pathologist work with him at 2 (all states have early intervention services, they are in-home and free)...by 3 1/2, the kid wouldn't STOP talking.
There are no red flags here...sounds like a pampered kid who's got to start working for things...and didn't have to before. Like the other mom said, not trying to be rude--but take solace in the fact that his preschool teacher is probably not educated in the matter...usually, that type of education is done with teachers (like pre-k and up). She probably doesn't know what she's talking about. However, I WOULD have early intervention services in the home to determine if there are issues and what to do....
Does anyone else here remember that there wasn't "autism" a few decades ago...now it's "the diagnosis of the century". To be honest, it's quite rare...numbers of TRUE cases vs. suspected made autism awareness jump and say 1 in 150 (it's more like 1 in 2500).
Please don't worry--take this in stride, and having someone in to work with him now will get his speech going...fyi, he's probably thinking a lot, but without words--whining and having a fit is about all he can do to express himself...