Another vote for the functional approach, all the way. Being HG+ means you are not neurotypical, period, but the ways you are atypical may sometimes add up to an ASD diagnosis and sometimes not. (There is also the theory that there are gifted/ADHD/ASD traits which are all part of some much broader autistic spectrum than is currently believed, you may want to check out "bright not broken".)
Personally, it him it is the theory of mind-blindness that should be the ultimate test, not a collection of traits, and I do not think that parents should be forced to push for a premature, possibly inaccurate diagnosis simply to get their children services that schools or insurance might otherwise be unwilling to provide even though the functional impairment is clearly there.
However, I think kitkat24 has written an excellent post that shows how sometimes it is really the degree to which traits are present and impair functioning should drive the diagnostic/therapeutic process. It's not black and white - from her pits, I can gauge exactly in retrospect why in the event, even though almost all of those traits were there in DS case, they were not there "enough", kWIM? For instance, I remember thinking o my god when he sat down in front of the washer,staring at the spin cycle. But he did that exactly once, and so it did not count as a red flag in the end

Last edited by Tigerle; 12/16/14 01:29 PM.