I have also been recently diagnosed Aspergers. Just a few days ago I came upon a site about POTS and realized I have many of the symptoms.
They started occurring fairly recently. A few years ago my skin started becoming red and blotchy whenever I got hot; it was particularly noticeable in the shower. I also noticed that my heart would beat hard at unusual times, such as when I wasn't exerting myself or even lying in bed. A little later I started intermittently experiencing severe head rushes upon standing. I have over time noticed various other symptoms that could be related to POTS, such as sensory sensitivity, stomach problems, and absence of sweating, but I'm not sure how long these have been occurring. I'm seventeen, so my symptoms seem to be following the timeline for teen POTS mentioned on a website I visited, where symptoms begin around age 13 and peak around age 16. I should be visiting my primary care doctor soon to find out whether I actually have POTS or not.
I had an experience similar to taniaaust1's when I was in elementary school. A few times my legs suddenly crumpled under me and it took a few moments for them to begin working again. If that is, in fact, related to POTS and I do have it, those would have been my first symptoms.
Around third grade it also became apparent that I have some mental impairment which has caused much trouble throughout school. I recently became aware that I constantly have some amount of confusion, though it varies greatly in strength. It seems related to my other POTS-like symptoms. If this confusion is the cause of the slowness I have had all my life and is caused by POTS, that would set my major symptoms much earlier.
How severe can mental impairment caused by POTS be? Sometimes I can become so "foggy" that I can barely talk and have trouble forming thoughts. Also do any of your eyes start to twitch uncontrollably when they get fatigued?