I had the same concern, esp. about DD. It didn't seem normal that she wasn't interested in toys and play the way other kids were. If a kid does not do any imaginative play (as in, they don't understand it), that is a sign of autism. But some kids "understand" pretend play, but aren't all that interested. Your DS does seem kind of young to have lost all interest already. DS was into his trains at 2-3 and made up stories about his trains. He liked thomas the train videos. DD seemed to "get" imaginative play but just wasn't that into it. Looking back, I think it was a combination of her personality (being very logic oriented) and the fact that she has ADHD and couldn't stay on task for very long. So she would go from one thing to the next, to the next. Seemed to fiddle with toys and carry them around more than actually play with them. She did do very well with puzzles and would put a good deal of focus into them. And she loved listening to books. Both of my kids were also very into Minecraft in preschool and spent a lot of time building things. It's a computer game, but at least there is some creativity involved. I think we got the game when DS was 3.5 and DD was almost 5. And they are still into it now 3 years later.
