I have tried to pay attention to drawing ability/LD issues and I have found
no correlation at all. What I have observed so far is that there is no
relationship at all between kids with LD or kids with typical academic
excellence and art ability. The kids who draw the best are the kids who draw
the most. Perhaps kids who spend a lot of time alone and/or have gotten
positive attention from their drawings (as Chuck Close describes) draw well
for those reasons.
Therefore, only from my classroom observations, I think drawing/art ability
transcends any typical assessment of learning ability/disability.