My five year old son is Autistic, but there are several types. He has Aspergers which is where he understands what he's told, he is very smart, has an awesome memorie and is good with numbers, but has a hard time speaking. His mind works faster then he can express himself. We had no idea he had this until a year ago after he had been tested. No one else in my family or his father's was Autistic, but the doctors said because I had a terrible pregnancy, and my son was born a month early, plus it was a very difficult birth that it all could have had something to do with it.It's more common in boys that were born early. We really had no idea this would happen. I was honestly more afraid he would be epileptic, because that runs in the family.I was told it's like any other problem. One thing could be slightly off in the childs development that could cause it. If you're worried your child might be autistic I suggest getting them tested. There are many different types, but don't be ashamed of it. I was worried at first when it came to my son, but when they tested him his level of education is way above others his age. So don't worry if they are. There are many programs out there that will work with you and your child as they have with me and mine.I hope this helps and everything works out for you.