Thanks for the responses - I had never heard the term until I read the blog last week. When my son (now 10) was 4 our pediatrician suggested we make an appt with a psychologist. The psychologist didn't diagnose anything specifically, for which I'm thankful since most of the behavioral/social challenges resolved themselves. But. I know that ASD had been suspected and it has continued to be hinted at by some who know him. He read early (2.5 - 3) and with good comprehension (probably at about a 3rd grade level by kindergarten, though he wasn't really interested in the stories (fiction) that were written for his reading level - they were all about social dynamics of mid-elementary school. He was much happier with nonfiction until he was about 7 or 8 yrs old. He's still not the most socially adept kid in the world and likely will never be, but he has friends now and likes to be around other kids. It just took him until about first or second grade for his desire fror friends to kick in.
I do wonder how many early readers who are "just" very gifted kids and who have some degree of social awkwardness (especially as little kids because they just aren't interested in what their same-age peers are interested in) are being diagnosed (erroneously) as on the spectrum. I know there are certainly early readers who have other issues that legitamately place them on the spectrum, but there was a siginficant amount of worry generated for us.