Both my children have mild hypotonia (DS more so than DD--he was in therapy for this as a baby), meaning they have low muscle tone. However, DS manages to be quite coordinated despite it. He has an amazingly strong and accurate throwing arm. This is a child who could not sit up till 9 months! DD is still noticeably behind on large motor skills but manages to do passably at some things due to sheer force of will. Interestingly, low muscle tone, prodigious memorization skills, mild ASD (not diagnosed, but strongly suspected, and not just by me), and giftedness all run in my family, going back several generations. What's more, they seem to exist as a bit of a "package deal" in many cases, though not everyone has all of them. I absolutely do not possess the memorization skill myself, but it's quite recognizable to me, having sat through my father (who's a scientist, by the way!) reciting reams of poetry at the dinner table when I was a child.
