DS read early, but he was a hider so it's hard to say exactly when.... 3ish maybe? I know he had at least a couple words before then, but around his 3rd birthday was when he seemed to put some effort into it (all the while insisting he wasn't...) and he was fluent well before 5.
He's still a voracious reader at 10, but his main strengths are in math and science. Early reading hasn't translated into anything like good spelling, but he writes reasonably well (if the topic is interesting). I think the common thread is logic... His early reading was like working out the logic of letters and sounds, his math strengths are logic strengths (not, for instance, notable speed or fact recall....) and his science ability is almost entirely in experiment design and analysis, having never memorized names of dinosaurs or planets or anything like that. So it kind of makes sense that the early reading skills might be related to later math... although I think there are other routes to early reading that might not be logic/math related.
