IMHO- a child who learns to read very early (I'm going to say early as 3 or earlier) on his/her own and without heavy hothousing, is very likely to test gifted later. But that does not exclude a child who does NOT learn to read early from being gifted. I think Ruf overemphasizes it because it's an "eye-popper" if your 2 year old is reading in the grocery cart. It's the kind of easily identifiable thing that jumps out to parents and other people.
My now DYS 8 year old learned to read in BOB books at 4 1/2. He was reading chapter books 6 months later when he started K. By 1st grade, he was reading at a 6th grade level. By the beginning of 3rd (with a mid-year skip in there) he was reading at a high school level.
I also tend to disregard Ruf's signs for him because he was a heavily medicated preemie who basically looked like a loaf of bread until about 6 mo. old when he came off the medication. His timeline was all his own. But he went from barely making noises to speaking paragraphs at 14 mo.
